In a sign new Chief Executive Sergio Ermotti -- appointed after the scandal -- is beginning to make his mark on the crisis-shaken bank, he also gave new responsibilities to two of his rivals for the top job: Ulrich Koerner and Bob McCann.
Lofts, the chief executive of the UBS Americas business who had already held the risk position from 2008 until 2010, replaces Miskovic immediately, UBS said in a statement, adding she would leave the bank.
UBS shares were down 0.8 percent at 11.09 francs by 0956 GMT, underperforming a 0.15 percent weaker European banking sector <.SX7P>.
A UBS spokesman said Miskovic's departure was not related to losses allegedly racked up by London-based trader Kweku Adoboli.
But the scandal had raised questions over her future as the bank reviewed its control procedures and admitted risk systems had detected unauthorized activity but failed to respond.
As I have stated before, one of my main priorities is to continue to reinforce the bank's risk framework, Ermotti said in a memo to staff.
During his previous term as group CRO ... (Lofts) demonstrated that he has the broad skills and experience and the strong leadership needed to run our risk organization decisively in a turbulent market environment.
Miskovic, only in the risk role at UBS since January, was not immediately available for comment.
She had been head of risk at U.S.-based financial services group State Street from 2008 to 2010. From 1996-2002, she was chief risk officer at Lehman Brothers, the U.S. investment bank that collapsed three years ago. Before that she worked at Morgan Stanley
The other management promotions could be seen as a move to dampen strife among top management triggered by Oswald Gruebel's resignation in September following the trading scandal.
Before Ermotti's temporary appointment as CEO was sealed as permanent last month, senior executives including McCann and Koerner had jockeyed for position, sources had told Reuters.
McCann, CEO of Wealth Management Americas since 2009, will also take over as CEO Americas, and Koerner was appointed CEO UBS Group Europe, Middle East and Africa --- the job Ermotti previously held -- in addition to his current role as Group Chief Operating Officer and CEO Corporate Center, UBS said.
The promotion of McCann, who came to UBS after a high-profile stint at Merrill Lynch & Co., is an acknowledgement of his success reviving the Swiss bank's U.S.-based brokerage unit, formerly known as Paine Webber.
UBS Wealth Management Americas, the smallest of the four major Wall Street brokerages, in October reported a swing to a third-quarter profit. McCann is targeting $1 billion in pretax profit for the business, in part by getting brokers to sell more mortgages and realising more synergies with the UBS investment bank.
Koerner, lured away from Credit Suisse
UBS declined to comment on Thursday on the status of its internal probe into the trading scandal.
In October, Ermotti said the bank had accepted the resignation of the two co-heads of global equities, Francois Gouws and Yassine Bouhara, over the unauthorized trades and said disciplinary action against other members of staff was pending.
(Additional reporting by Silke Koltrowitz; Editing by Hans-Juergen Peters)