Michael Rosenberg, co-head of the global credit collateralized debt obligation group at UBS, has been transferred from the firm's Stamford, Conn. office to London. Kris Kagel, spokesman in New York, said basing Rosenberg in London will allow UBS to have a more consistent focus on Europe and European clients. Rosenberg did not return calls. Jeff Herlyn, who co-heads the business with Rosenberg, continues to be based in Stamford.