UBS is set to begin cutting jobs at its investment banking arm as early as Wednesday, the Wall Street Journal reported.
The Swiss bank will notify roughly 400 bankers in corporate finance but also fixed income and equities they are being laid off, part of a larger scaleback of its securities unit, the Wall Street Journal reported in its Wednesday edition.
It cited undisclosed sources involved in the cuts.
More job cuts could quickly follow, the paper said.
Separately, the Financial Times reported the UBS revamp could ultimately spark several thousand job losses, but that cuts may not be finalised in time to disclose alongside third-quarter earnings, scheduled for October 30.
The FT reported UBS' investment bank was looking to continue exiting capital-intensive areas in fixed income trading such as long-end flow rates and global correlation trades.
Less than two weeks ago, UBS said it had not yet finalised an ongoing business review, but flagged further cutbacks.
"I am ... determined to take all actions necessary to tackle the current challenging market environment and paradigm shift in our industry," UBS Chief Executive Sergio Ermotti said in a memorandum to staff on Oct 13.
UBS has already pledged to cut 3,500 jobs as part of earlier cost cuts, but this is seen as too little by most analysts given a dramatic slowdown in investment banking business and tighter capital rules governing riskier business.
UBS was not immediately available for comment.
(Reporting By Katharina Bart; Editing by Helen Massy-Beresford)