Standard Chartered and HSBC could pay more than $2 billion to settle U.S. money-laundering charges. (Sang Tan/AP)

Two of Europe’s largest banks are close to handing over a total of more than $2 billion to resolve allegations that they flouted U.S. anti-money-laundering laws, according to officials and people familiar with the matter.

The twin investigations are part of a stepped-up effort by federal prosecutors and regulators to clamp down on funding sources for drug traffickers, terrorists and countries under sanction. But the lack of criminal prosecutions has left some analysts skeptical about whether fines alone will deter this behavior.

“Until bank officials that knowingly violate anti-money-laundering laws are held criminally liable, we’re not going to see rigorous compliance with federal regulations,” said James Gurule, a former undersecretary of enforcement for the Treasury.

On Thursday, Standard Chartered Bank said that it expects to pay $330 million to settle all pending cases of alleged violations of U.S. sanctions. The Justice Department and banking regulators have been investigating whether the London-based bank laundered money on behalf of Iranian banks and companies.

Another London-based bank, HSBC, faces a $1.8 billion fine for allegedly helping clients with ties to drug trafficking and terrorists gain access to the U.S. financial system, Reuters reported Thursday.

Global banking giants, including Barclays, Credit Suisse and Lloyds, have been hit with massive fines and penalties for ignoring U.S. sanctions. Many of these banks have faced criminal and civil charges, but prosecutors have yet to put senior executives or even mid-level employees on trial.

Daniel E. Karson, chairman of corporate investigations firm Kroll Advisory Solutions, said high fines will encourage banks to be more vigilant. No bank, he said, wants to face damage to its reputation, as that could hamper its operations.

“The government is getting some pretty significant settlements,” he said. “If you get a consent order and a major civil prosecution and the payment of a huge fine, you’re ahead of the game.”

Karson said the trouble is that banks say they will comply with anti-money-laundering statutes but also give employees incentives to pursue big business opportunities.

“Banks are up against a system of incentives which at times flies in the face of compliance. If someone’s bonus is based upon how much business they bring in, they may let some accounts slide,” he said.

That’s precisely why it is crucial for prosecutors to go after individuals to hold them up as examples, said Gurule, the former Treasury official who is now a professor of law at the University of Notre Dame.

In HSBC’s case, the bank is entering into a deferred prosecution deal, whereby it could delay or forgo criminal prosecution in exchange for paying a fine, admitting wrongdoing and improving its compliance controls, according to a person familiar with the matter who spoke on condition of anonymity because the agreement has not been finalized. If the bank runs into more trouble, the Justice Department could prosecute.

A spokesperson at HSBC said that “the nature of any discussion is confidential.”

HSBC told investors last month that it increased its reserves by $800 million, to $1.5 billion, to cover potential fines, settlements and other costs related to the money-laundering probe. At the time, the bank said the final expenses could be significantly higher than that amount.

Allegations of misconduct at HSBC came to light earlier this year when the Senate permanent subcommittee on investigations released a report accusing the bank of laundering money for Mexican drug cartels and organizations that financed terrorism.

In one instance, the year-long Senate investigation found that HSBC employees in Mexico transported $7 billion to affiliates in the United States in one year, raising red flags that the money was derived from drug deals in the United States.

Legal experts say it is difficult to prove criminal liability in these kinds of cases because it is often unclear whether bank employees or managers intentionally ignored the law. But others argue that there should be no trouble indicting bank officials who air their dirty deeds in e-mails, as executives did at Standard Chartered.

According to New York’s financial regulator, who first leveled charges against Standard Chartered in August, one of its executives said in an e-mail: “You . . . Americans. Who are you to tell us, the rest of the world, that we’re not going to deal with Iranians.”

New York regulators accused the British bank of scheming with the Iranian government to launder $250 billion from 2001 to 2007. The case was settled for $340 million over the summer as federal regulators forged ahead with their own case.