ZURICH/NEW YORK (Reuters) - Credit Suisse (>> Credit Suisse Group AG) said on Friday it would put aside more funds for a U.S. probe and other litigation about whether the Swiss bank deceived investors in risky mortgage-backed securities it had issued in the run-up to the financial crisis.

The Zurich lender's surprise move to tack on 277 million Swiss francs ($290.66 million) to legal reserves and revise fourth-quarter results of just two weeks ago comes one day after U.S. rival Morgan Stanley (>> Morgan Stanley) said it expected to pay $2.6 billion to resolve potential claims stemming from its sale of mortgage bonds before the financial crisis.

"Developments in industry-wide litigation and investigations in the United States relating to mortgages have resulted in an increase in provisions relating to this issue subsequent to the disclosure of the bank's preliminary 2014 results," Credit Suisse said in a statement late on Friday, without elaborating.

The U.S. government's examination of financial crisis-era mortgage abuses is now Credit Suisse's biggest legal worry, after it last year set aside a years-long U.S. probe into its dealings with Americans evading taxes by pleading guilty to a criminal charge and agreeing to pay more than $2.5 billion in penalties.

The Swiss bank now puts an estimate for legal issues that it hasn't provisioned for at up to 1.8 billion francs, from what it had originally put at up to 1.3 billion francs.

In December, a New York state judge rejected a motion to dismiss a New York case against the Swiss bank over accusations that it deceived investors in mortgage-backed securities.

New York Attorney General Eric Schneiderman filed the case in 2012, accusing the bank of misrepresenting the quality of loans underlying securities issued in 2006 and 2007.

Investors suffered $11.2 billion in losses on the securities, according to Schneiderman's lawsuit.

Matt Mittenthal, a spokesman for Schneiderman, declined to comment on Credit Suisse's legal provisions.

Schneiderman is co-chair of a joint federal-state working group created in 2012 by President Barack Obama to go after misconduct in the pooling and sale of mortgage securities that helped lead to the 2008 financial crisis.

Credit Suisse has said it would appeal the ruling allowing the lawsuit to go forward. Drew Benson, a New York-based spokesman for Credit Suisse, declined comment on Friday beyond the bank's statement.

In August, Bank of America (>> Bank of America Corp) agreed to pay over $16 billion, Citigroup (>> Citigroup Inc) in July agreed to pay $7 billion, and JPMorgan Chase & Co (>> JPMorgan Chase & Co.) agreed to pay $13 billion in 2013 in settlements with U.S. state and federal authorities over charges they misled investors into buying troubled mortgage-backed securities.

(Reporting by Katharina Bart and Karen Freifeld; Editing by Bernard Orr)

By Katharina Bart and Karen Freifeld