FRANKFURT (REUTERS) - Deutsche Bank is bracing for more than 300 million euros (S$487 million) in charges linked to suspected violations of United States sanctions on Iran, a German weekly reported on Sunday.

Deutsche Bank, Europe's biggest bank by assets, on Wednesday increased its provisions for litigation by 600 million euros to 2.4 billion euros, citing mortgage-related lawsuits and other regulatory investigations.

Without specifying its sources, the magazine Der Spiegel said the money set aside could be a sign US investigations of possible Iran-linked transactions had reached an advanced stage.

Deutsche Bank on Wednesday declined to lay out in detail why it had increased provisions. On Sunday, it would not comment on the magazine report.

The US government is cracking down on foreign banks it accuses of undermining its effort to throttle Iran's economy. In the most prominent case, London-based Standard Chartered last year agreed to pay US$667 million (S$834 million) to settle charges it violated sanctions against Iran and other countries.

Other lenders in the crosshairs of US investigators include Commerzbank, Unicredit division HVB, and HSBC in Britain.

Der Spiegel said apart from the Iran probe, Deutsche Bank's 2.4 billion-euro legal provisioning included 500 million euros for a probe of suspected manipulation of interbank lending rates.

Several sources familiar with the investigation told Reuters on Thursday that German markets watchdog Bafin is set to rebuke Deutsche Bank over how it supervised its contribution to the setting of the lending rates.