The UBS equities unit provides clients with stock-related products and services, such as trading and lending. The equities group also provides research analyst reports on companies and industries.
Read MoreUBS trims executive ranks of Americas wealth management unit
A Deutsche Bank veteran, Leone joined UBS in 2008. He was most recently head of equities trading and risk in the Americas for UBS, a role he will keep. A Citigroup and DB alum, Chadha joined the bank in 2013 as head of derivatives for the Americas. He will also retain that role despite the new position.
The personnel changes to emerge Tuesday are the latest to the equities unit.
Naylor and Karofsky were made global co-heads in September when Mike Stewart moved to the UBS wealth management unit. Stewart had replaced co-heads Francois Gouws and Yassine Bouhara; the men resigned in 2011 after a multi-billion dollar loss from unauthorized trading.
The equities business appears strong despite the turnover.
UBS was named the top bank in Europe for equity derivatives in 2014 by various trade publications, and also received top or second-best rankings related to regular stocks ("cash equities") and stock-related financing, such as prime brokerage services to hedge fund clients in Europe and Asia.
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