Executives close to Mr. Humphreys speculate the British adman may make an offer for Ayer because of conflicting opinions with the Korean billionaire and media mogul regarding Mr. Humphreys' role in the agency's future growth.
Mr. Humphreys denied having any interest in buying Ayer from Mr. Choi. But the marriage of convenience between the two investors is on shaky ground following Mr. Humphreys' run for the $508 million Bloomfield Hills, Mich.-based Ross Roy Communications, a move he made minus Mr. Choi.
"My bid for Ross Roy is not something we wish to do together," said Mr. Humphreys. "But it doesn't affect Adcom and besides, Ross Roy may choose to go with the Omnicom offer." Ross Roy is expected to make a decision this week.
While Mr. Choi is unwilling to put up his own money for an acquisition, he is said to be opposed to any outside investment that would dilute his interest, leaving him without control of Ayer. He now holds better than a 90% stake, said executives familiar with the situation.
Should Messrs. Humphreys and Choi come to blows over plans for Ayer, agency management, including Chairman-CEO Steve Dworin, are prepared to seek either an equity position for themselves or a management buyout, said Wall Street sources.
Mr. Dworin could not be reached for comment.
Mr. Humphreys made two offers for Bates Worldwide, one last summer and another in early December, but was rejected by the Saatchi & Saatchi Co. board.
It also was one of several disagreements between Mr. Humphreys and Mr. Choi said to have strained relations between the men.
Mr. Humphreys, who has a less than 10% stake in Ayer, said the Bates bid was also made independently of Mr. Choi, though he had hoped to persuade Mr. Choi to make Ayer and Bates two U.S. sister companies with a shared international network called Bates/Ayer International.
Mr. Choi, president/owner of Seoul-based International Media Institution, teamed with Mr. Humphreys to acquire NW Ayer in 1993. The agency has billings of $861.2 million.