ValueClick Inc. on Wednesday said that its longtime chief executive has retired and has been succeeded by the company’s chief operating officer. The change is effective immediately.

The Westlake Village digital marketing company said that 67-year-old James Zarley will continue with the company as executive chairman. Replacing him is John Giuliani, 50, who became chief operating officer in April and already sits on the board.

ValueClick offers products and services that enable marketers to advertise and sell their products on Internet sites. Giuliani joined the company in August 2011, when it acquired Dotomi, the Chicago technology company where he was chief executive. He ran the Dotomi division until his promotion to COO.

Zarley first served as ValueClick chief executive between 1999 and mid-2007, and returned to the job in April 2010.

The board’s current chairman, Martin Hart, will step down from that role but remain a director and chairman of the board’s compensation committee.

ValueClick shares closed up 34 cents, or 2 percent, to $19.12 on the Nasdaq.