UBS on Wednesday announced management changes within its investment bank unit and also altered the organization of its risk control operations.

The changes are meant to help the investment bank overcome risk management deficiencies after it wrote down $38 billion in investments tied to the struggling mortgage market.

The bank said Daniel Coleman is now heading its global equities functions. Former co-head John Wall will become the chief of proprietary trading. Both will report to Chairman and CEO of UBS Investment Bank Jerker Johansson.

Johansson will take charge of the bank's Fixed Income, Currencies and Commodities on an interim basis. He is replacing Andre Esteves, who will focus full-time on his role as Chairman and CEO of UBS Latin America, based in Brazil.

The bank also announced changes to its Group Risk division.

Former Morgan Stanley chief risk officer Thomas Daula will take up the same role at the investment bank. Daula will also hold the title of chief credit officer. He will report to Johansson and Joe Scoby, Group chief risk officer.

Philip Lofts was appointed as the group's chief operating officer.

The bank is also creating a new unit to control the firm's overall risk exposure across credit, market and country risk. The new group will be called Group Portfolio and Concentration Risk Control, combining formerly separate market risk and credit risk divisions.

These changes are designed to establish a best in class Risk Control team with an overall view of all risks, said Scoby. The creation of an integrated portfolio and concentration risk group will help break down any remaining information silos between the different risk functions.