Banking giant UBS (UBSG.S) is in discussions to take over all or parts of Credit Suisse (CSGN.S), with the boards of Switzerland's two biggest lenders set to meet separately over the weekend, the Financial Times reported on Friday.

The Swiss National Bank and regulator FINMA are organising the talks in an attempt to build confidence in the country's banking sector, the report said, citing people familiar with the matter.

On Friday evening, Swiss regulators informed their counterparts in the United States and United Kingdom that the merger of the two banks was their "Plan A" to salvage the confidence in Credit Suisse, the report added.

Several other options are also under discussion between the two banks as both sides try to evaluate regulatory constraints in different jurisdictions, the newspaper reported.

The Swiss central bank's focus is on agreeing a straightforward solution before markets open on Monday, the report said, adding there is no guarantee a deal will be reached.

Credit Suisse and UBS declined to comment on the report. The Swiss National Bank and FINMA did not immediately respond to Reuters request for comment.

Bloomberg reported on Thursday that UBS Group AG and Credit Suisse were opposed to a forced merger, with UBS preferring to focus on its own wealth-centric strategy and reluctant to take on risks related to its smaller rival.

Credit Suisse is biggest bank to be ensnared in the market turmoil following the collapse of U.S. lenders SVB and New York-based Signature Bank, forcing the Swiss lender to borrow up to $54 billion from Switzerland's central bank to shore up liquidity.