LONDON -- New York's top bank regulator on Monday threatened to strip Standard Chartered Plc. of its state banking license, saying the British bank was a "rogue institution" that hid $250 billion in transactions tied to Iran, in violation of U.S. law.

Standard Chartered strongly rejected the allegation.

"The group strongly rejects the position or the portrayal of facts as set out in the order issued by the DFS," Standard Chartered said in a statement on Tuesday, adding that it does "not believe the order issued by the DFS (New York State Department of Financial Services) presents a full and accurate picture of the facts."

The Department of Financial Services said Standard Chartered "schemed" with the Iranian government and hid from law enforcement officials some 60,000 secret transactions to generate hundreds of millions of dollars in fees over nearly 10 years, also exposing the U.S. banking system to terrorists, drug traffickers and corrupt states.

The loss of a New York banking license would be a devastating blow for a foreign bank, effectively cutting off direct access to the U.S. bank market. Standard Chartered processes $190 billion every day for global clients, the New York bank regulator said.

Shares in Standard Chartered fell sharply in early trading Tuesday in London. Shares were down 16 percent to 1,237 pence compared with a 0.8 percent fall in Europe's bank index.

Report alleges 'obvious contempt' for regulations
In an unusual look inside a bank, the regulator described how Standard Chartered officials debated whether to continue Iranian dealings. In October 2006, the top official for business in the Americas, whom the regulator did not name, warned in a "panicked message" that the Iranian dealings could cause "catastrophic reputational damage" and "serious criminal liability."

A top executive in London shot back: "You f---ing Americans. Who are you to tell us, the rest of the world, that we're not going to deal with Iranians." The reply showed "obvious contempt for U.S. banking regulations," the regulator said.

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Standard Chartered is the third British bank to be ensnared in U.S. law enforcement probes this summer. Barclays Plc. agreed to pay $453 million to settle U.S. and U.K. probes that it rigged a global lending benchmark in June. A month later, a U.S. Senate panel issued a scathing report that criticized HSBC Holding Plc.'s efforts to police suspect transactions, including Mexican drug traffickers.

In its statement, Standard Chartered said it shared with U.S. agencies an analysis that demonstrated it "acted to comply, and overwhelmingly did comply" with U.S. regulations. Standard Chartered put the total value of Iran-related transactions that did not follow regulations at less than $14 million.

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The statement said "well over 99.9 percent" of the questioned transactions with Iran complied with all regulations.

"The group was therefore surprised to receive the order from the DFS, given that discussions with the agencies were ongoing," Standard Chartered said. "We intend to discuss these matters with the DFS and to contest their position."

The Department of Financial Services declined further comment. The Representative Office of Iran in Washington was not immediately available to comment. The Treasury Office of Foreign Assets Control, which enforces U.S. economic and trade sanctions against targeted countries, declined to comment.

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Standard Chartered, a financier in emerging markets, is the sixth foreign bank since 2008 to be implicated in dealings with sanctioned countries such as Iran in investigations led by federal and New York law enforcement officials.

Four banks -- Barclays, Lloyds, Credit Suisse Group and ING Bank -- have agreed to fines and settlements totaling $1.8 billion. HSBC currently is under investigation by U.S. law enforcement, according to bank regulatory filings.

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The New York regulator, headed by former prosecutor Benjamin Lawsky, ordered Standard Chartered to explain why the bank should not lose its state license and the ability to process dollar transactions. Lawsky also ordered the bank to bring in an outside consultant to monitor its transactions.

"Standard Chartered Bank operated as a rogue institution," Lawsky said in the order.

Deloitte cited
In an unusual move, the regulator also found fault with an outside consultant -- Deloitte LLP -- because the firm "apparently aided" the bank in its deception.

A report by Deloitte "intentionally omitted critical information" when submitted to regulators, it said.

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Deloitte was hired to conduct a review after Standard Chartered in 2004 was ordered by New York and federal regulators to correct anti-money laundering lapses.

The so-called "look back" review was supposed to identify suspicious transactions between 2002 and 2004. But at one point, Standard Chartered asked Deloitte to "delete" references to certain improper Iranian transactions, according to the New York order.

In a subsequent email, a Deloitte partner said the firm had "agreed" to the request because it was "too politically sensitive for both (Standard Chartered) and Deloitte. That is why I drafted the watered-down version." In 2007, that report enabled Standard Chartered to show regulators it had corrected flaws in its anti-money laundering systems.

In a statement on Monday, Deloitte said its financial advisory service division "performed its role as independent consultant properly and had no knowledge of any alleged misconduct by bank employees. Allegations otherwise are unsupported by the facts."

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Lawsky's investigation is extraordinary because probes into how banks carried out transactions tied to Iran primarily have been led by the district attorney's office in Manhattan and the U.S. Justice Department.

His probe is another sign that the regulator intends to join the New York attorney general and Manhattan district attorney in being a top financial watchdog. The DFS was created last October, effectively assuming oversight of two former banking and insurance regulatory agencies that were abolished.

Probes by the Manhattan district attorney and U.S. Justice Department date to 2006 and have targeted some nine banks. Barclays agreed to pay $298 million in 2010 after admitting it processed payments for clients tied to Cuba, Sudan and other countries. Lloyds and Credit Suisse agreed to pay settlements of $350 million and $536 million.

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In June, ING agreed to pay $619 million to settle allegations that it, too, violated U.S. sanctions against Cuba, Iran and other countries. It was the biggest fine levied against a bank for sanctions violations.

The Justice Department, working with the FBI in New York, is also investigating Standard Chartered's activities for violations of U.S. sanctions.

Standard Chartered, founded in 1853, is headquartered in London, but specializes in financing in Asia, Africa and the Middle East.

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Chairman John Peace, CEO Peter Sands and Finance Director Richard Meddings could not be reached for comment, and the bank declined to comment beyond its brief statement.

Reuters and The Associated Press contributed to this report.

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Luke Macgregor / Reuters, file

A HSBC bank logo is highlighted by the sun in London in this file photo taken March 1, 2010.

A "pervasively polluted" culture at HSBC allowed the bank to act as financier to clients moving shadowy funds from the world's most dangerous and secretive corners, including Mexico, Iran, Saudi Arabia and Syria, according to a scathing U.S. Senate report issued on Monday.

The report [link to PDF here] which comes ahead of a Senate hearing on Tuesday, said large amounts of Mexican drug money likely passed through the bank. 

HSBC's U.S. division provided money and banking services to some banks in Saudi Arabia and Bangladesh believed to have helped fund al-Qaida and other terrorist groups, according to an Al-Jazeera story on the report.

While the big British bank's problems have been known for nearly a decade, the Senate probe detailed just how sweeping the problems have been, both at the bank and at the Office of the Comptroller of the Currency, a top U.S. bank regulator which the report said failed to properly monitor HSBC.

"The culture at HSBC was pervasively polluted for a long time," said Senator Carl Levin, chairman of the U.S. Senate Permanent Subcommittee on Investigations, a Congressional watchdog panel.

The report comes at a troubling time for a banking industry reeling from a multi-country probe into the manipulation of global benchmark rates. Last month, rival British bank Barclays agreed to pay a $453 million fine to settle a U.S.-British probe into the rigging of the benchmark interest rate known as the London interbank offered rate, or Libor.

Lax controls
The report caps a year-long inquiry that included a review of 1.4 million documents and interviews with 75 HSBC officials and bank regulators. It will be the focus of a hearing on Tuesday at which HSBC and OCC officials are scheduled to testify.

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In a statement emailed to NBCNews.com, the bank said: 

We will apologize, acknowledge these mistakes, answer for our actions and give our absolute commitment to fixing what went wrong. We believe that this case history will provide important lessons for the whole industry in seeking to prevent illicit actors entering the global financial system.

The report also contained strong criticism of the OCC, saying the regulator failed to crack down on the bank despite multiple red flags, allowing money laundering issues "to accumulate into a massive problem".

The failings and lax controls inside HSBC included an inability to properly monitor $15 billion in bulk cash transactions between mid-2006 and mid-2009, inadequate staffing and high turnover in the bank's compliance units, the report said.

HSBC ignored risks in doing business in countries such as Mexico, a country rife with drug trafficking, it said.

Between 2007 and 2008, HSBC's Mexican operations moved $7 billion into the bank's U.S. operations. According to the report, both Mexican and U.S. authorities warned HSBC that the amount of money could only have reached such a level if it was tied to illegal narcotics proceeds.

The focus of the Senate probe was HSBC's U.S. operations, which has its main office in New York. HSBC used the U.S. unit as a selling point to clients outside the United States, touting its ability to handle U.S. dollar transactions.

Red flags
The report described that among HSBC's problems was the bank's compliance division being unable to battle the suspect money. High turnover of top compliance officials made it difficult for reform to take hold, the report said. Employees were "overwhelmed" by a mounting number of suspect transactions that needed review.

HSBC, according to the report, helped move money for a Mexican foreign-exchange dealer called Casa de Cambio Puebla that served as a hub for laundered proceeds, according to the report.

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Between 2005 and 2007, there was a "growing flood" of U.S. dollars moving between the exchange house and HSBC, setting off red flags inside HSBC. Some bankers said the transfers were legal. One said the money came from Mexican landscapers working in the United States and routing money back home to their families.

HSBC ultimately closed the account in November 2007 after it received a seizure warrant from the Mexican attorney general seeking money tied to the exchange dealer, the Senate report said.

Some of the money that moved through HSBC was tied to Iran, the report said, which would violate U.S. prohibitions on transactions linked to it and other sanctioned countries.

Between 2001 and 2007, more than 28,000 transactions were identified by an outside auditor for HSBC that potentially could have run afoul of laws that prohibit transactions with sanctioned countries. Of those, 25,000 involved Iran. A smaller number required additional analysis to determine if violations of U.S. regulations had occurred, the report said.

In 2010, Wachovia agreed to pay $160 million as part of a Justice Department probe that examined Mexican transactions, according to a BBC report, which also said ING last month agreed to pay $619 million to settle U.S. government allegations that it violated U.S. sanctions against Cuba and Iran.

Reuters contributed to this report.

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