SAN FRANCISCO — After four years as Morrison & Foerster’s chief marketing officer, Joe Calve is leaving his post.

Calve didn’t respond to messages about his departure. The firm would only provide a statement in which managing partner Anna Erickson White said Calve had “achieved impressive results in business development and marketing initiatives” and wished him continued success.

During Calve’s tenure, MoFo has continued to polish its tech brand, helped by its high-profile representation of Apple in the smartphone wars. The firm under Calve also unveiled a new website, dubbed by Above the Law as “somewhat less crazy” than the interactive, offbeat design that preceded it.

Prior to joining MoFo’s New York office in 2010, Calve was the CMO at Proskauer Rose, and before that, global director of business development at White & Case. He also spent 15 years as an editor and business executive with American Lawyer Media.

MoFo won’t be alone in its search for a senior marketing and business development professional, says Melanie Bennet, who launched the senior-level management recruiting effort for Major, Lindsey & Africa in 2009 and now runs her own recruiting business, Bennet Consulting. By her count, 26 AmLaw 100 firms have CMO vacancies, including Latham & Watkins, Covington & Burling, Shearman & Sterling and Pillsbury Winthrop Shaw Pittman.

She added that these searches can take firms one to two years. “There’s almost always a gap [between CMOs]. It’s an opportunity for firms to revisit their strategy, take a breath and think about how they want to move forward,” she said. With compensation approaching “the partner-comp level,” hiring a CMO at an AmLaw 20 firm is “a big decision for firms, to define the position and find the right person.”

In an interview with the Yale Undergraduate Law Review in 2012, Calve said the days of CMOs moving from firm to firm after a few years were coming to an end. “When I got into the field, that movement was just starting, everybody was hiring, making ‘misstarts,’ and starting over. At that time, the biggest opportunity to increase your stature and salary was to move,” he said. “As the field has matured, the musical chairs aspect has died down.”

Contact the reporter at npierrepont@alm.com.