Larry Sonsini, the high-profile chief executive of Wilson Sonsini Goodrich & Rosati, is to step down as the West Coast technology leader prepares for a symbolic hand-over of power.

Sonsini, one of Silicon Valley’s most celebrated business figures and one of the US’ best known lawyers, is to step down as chief executive and hand responsibilities to John Roos, after 20 years managing the firm. He joined the firm in 1966.