Roger Naylor, the head of global equity derivatives at UBS in London, has been appointed co-head of global equities within its investment banking division, alongside Robert Karofsky, to replace Mike Stewart who is moving to the bank's wealth management division, according to memos seen by SRP.

Karofsky, who will join UBS from AllianceBernstein Holding in December, and Naylor will assume their new roles at the start of next year, said Juerg Zeltner, head of wealth management, and Andrea Orcel, head of the investment banking division.

According to the memos, Stewart has been named head of the investment products and services unit at the bank's private bank. He took over the equities business in October 2011 after UBS announced the restructuring of its investment bank following a $2.3bn loss from unauthorised trading. Stewart joined from Bank of America Merrill Lynch (BAML) in 2010.

In his new role, Stewart will succeed William Kennedy, who is leaving the firm. Investment products and services matches products to the recommendations of UBS's chief investment officer, analysing client portfolios and supporting customer advisers on topics such as wealth planning. Stewart will expand his role to include sales management, pricing and the bank's own profit and loss contribution.

According to Zeltner and Orcel, Stewart's appointment represents the commitment of the bank's senior management to "move talented and widely recognised executives across divisions to facilitate understanding and collaboration".

Naylor and Karofsky will be reunited at UBS, having worked together previously at Deutsche Bank. Naylor joined UBS from Deutsche in September 2012 where he was global head of equity derivatives and global head of equity risk.

Karofsky, who is the global head of equity trading at AllianceBernstein, began his career at Morgan Stanley and then joined Deutsche Bank in 2005 as head of North American equity before being appointed co-head of global equities at the bank.

Naylor will continue to be based in London, while Karofsky will be located in New York.

A UBS spokesperson confirmed the content of the memos.