Sydney-based partner Guy Alexander has been appointed co-practice group leader of Allens Arthur Robinson's M&A and capital markets group.

A partner of the firm since 1993, Alexander replaces Ewen Crouch, who will remain an active partner in the group alongside his role as chairman of the firm.

Alexander will be co-practice group leader and co-head of the M&A team with Melbourne-based partner Jon Webster.

"We are rearranging the MAC team across industry lines so that we can further aggressively pursue opportunities in the marketplace," Alexander said.

"The Allens MAC team has an impressive depth of talent and breadth of experience as shown by the fact that the M&A practice was rated among the top 10 in the world by three different league tables in 2009.

"Ewen has made a significant contribution in leading the group to the head of the market and making sure that a succession plan was in place to ensure a seamless transition," he added.