Xoma Corp. has named John Castello president...

Xoma Corp. has named John Castello president and chief executive of the Berkeley-based biotechnology firm.

Castello is the former president and CEO of the Swiss pharmaceutical firm Ares Serono Group.

Castello joined Ares Serono in 1986 as president of the Serono diagnostics division and served as president of the parent company from 1988 through August, 1991.