Arthur Kingsbury, 47, is leaving as president-chief operating officer of VNU USA and its subsidiary, BPI Communications, on March 1. He will become a consultant to the company. No successor has been named. John Babcock, president of VNU-owned Adweek Magazines Group, had been rumored for the top spot, but he demurred. "I don't think it would be someone like me," said Mr. Babcock. "I have more of a sales and marketing background. I think they are looking for someone more on the financial side for mergers and acquisitions."