Chiat / Day in London Breaks From Merger : Advertising: Branch of L.A. agency separates from marriage with TBWA, citing potential client loss.

The fiercely independent London office of Chiat/Day won’t be part of the agency’s merger with Omnicom’s TBWA advertising agency.

Andrew Law, managing director of Chiat/Day’s London operation, said Wednesday that his business will become a “floating agency” within the Omnicom network and will answer directly to Omnicom’s board.

Chiat/Day, Los Angeles’ best-known advertising agency, agreed in February to merge with New York-based TBWA. Executives from both agencies hailed the deal as “the perfect marriage,” but it didn’t sit well in London.

Law said his office stood to lose half its business because of conflicts with TBWA’s London operation. Law said, for example, that Chiat/Day London clients include the Body Shop, a cosmetics retailer, while TBWA represents the skin care company Nivea.

Law also cited a “culture clash” with TBWA. “We are hands-on and entrepreneurial, while they operate more in the usual way, more disciplined, you could say,” Law said.

Chiat/Day’s London operation employs 50 people and has annual billings equivalent to $60 million, a fraction of Chiat/Day’s worldwide billings of $860 million. Omnicom is a global giant whose agencies include BBDO Worldwide, DDB Needham Worldwide and San Francisco’s Goodby, Silverstein & Partners.

Law said he worked out the arrangement with Omnicom at a recent meeting with Omnicom Chairman Bruce Crawford in New York. An assistant to Crawford said he was in meetings Wednesday and wasn’t available for comment.

As previously reported, the merged agency, to be called TBWA-Chiat/Day, will be based in New York and headed by TBWA’s chairman, Bill Tragos. Jay Chiat, Chiat/Day’s chairman and principal shareholder, will become a consultant to Omnicom.