Shares in UBS (UBSN.VX: Quote, Profile, Research, Stock Buzz)(UBS.N: Quote, Profile, Research, Stock Buzz) were down 7 percent in early trading on Monday amid expectations the bank could announce more writedowns and job cuts as early as this week.
Swiss newspaper Sonntag said on Sunday that UBS would write down at least another $2 billion on illiquid assets and cut a further 8,000 jobs.
UBS shares were down 6.8 percent at 10.60 Swiss francs at 0715 GMT, when the DJ Stoxx European banking sector index was down 5.2 percent.
Shares in UBS, the world's largest wealth manager in terms of assets, had already fallen 7 percent on Friday as traders said rumors swirled of a profit warning and more writedowns in the first quarter.
The bank, one of Europe's hardest-hit in the crisis, has already written down more than $49 billion since mid-2007 and cut over 7,000 jobs, mostly in investment banking.
UBS declined to comment on the rumors on Friday and no one at the bank could immediately be reached for comment on Monday.
(Writing by Lisa Jucca; Editing by Greg Mahlich)