UBS Group AG has offered to buy Credit Suisse for up to $1 billion, with the Swiss government planning to change the country's laws to bypass a shareholder vote on the deal, the Financial Times reported on Sunday.

The proposed all-share deal between Switzerland's two biggest banks is set to be signed as soon as Sunday evening, the report said, adding that the deal will be priced at a fraction of Credit Suisse's closing price on Friday.

An offer was made on Sunday morning with a price of 0.25 Swiss francs ($0.27) a share to be paid in UBS stock, the newspaper said, citing people familiar with the matter. Credit Suisse's shares closed at 1.86 Swiss francs on Friday.

UBS in talks to acquire embattled Credit Suisse

UBS has also insisted on a 'material adverse change' that voids the deal in the event its credit default spreads jump by 100 basis points or more, the report added.

Credit Suisse declined to comment, while UBS Group and the Swiss government did not immediately respond to Reuters request for comment.

UBS is examining a takeover of Credit Suisse that could see the Swiss government offer a guarantee against the risks involved, two people with knowledge of the matter told Reuters on Saturday.