Gary Trimm, chief executive officer at on-demand technology firm Concurrent (Nasdaq: CCUR) is retiring as of April 23, the company said Wednesday.

Trimm also is leaving the board of directors. Concurrent’s CEO since 2004, Trimm will act as a part-time consultant to the company.

Replacing Trimm will be Dan Mondor, a veteran of the telecommunications industry. He most recently served as president of Mitel Networks. Earlier in his career, he worked for Nortel and Siemens.

Mondor also will serve on Concurrent’s board.