(Reuters) - UBS in February had concluded that buying its stricken competitor Credit Suisse was not desirable, but that further analysis was needed, an SEC filing showed on Wednesday.
UBS had been assessing the possible impact of a transaction with Credit Suisse since December, the filing showed.
In March UBS agreed to takeover its struggling rival Credit Suisse for 3 billion Swiss francs ($3.37 billion) and said it would assume up to 5 billion ($5.61 billion) in losses, as part of a deal hastily arranged by Swiss authorities.
The Swiss authorities and UBS Group AG (SIX:UBSG) have been racing to close the takeover as soon as possible in an effort to retain the lender's clients and employees, Reuters has reported.
Last month, UBS secured temporary approval from European Union antitrust regulators, but still needs to seek clearance under EU merger rules, while the U.S. Federal Reserve approved the UBS Group's acquisition of Credit Suisse's U.S. subsidiaries.