Google’s Top Ad Executive to Leave for Venture-Capital Firm

Sridhar Ramaswamy is joining Greylock Partners and will be replaced by Prabhakar Raghavan

The executive at the helm of Google’s juggernaut online advertising business is stepping down, a rare shake-up at the highest echelons of the search giant.

Sridhar Ramaswamy, who has overseen ads at Google for the past five years, is taking a new role at venture-capital firm Greylock Partners, the investment firm said in a blog post Monday. In an email, a Google spokeswoman confirmed the move.

Mr....