NEW YORK (CNN/Money) - AOL Time Warner Inc. is searching for a new chief executive for its America Online division, a spokeswoman for the company told CNNfn Friday.

Shares of AOL Time Warner (AOL: up $0.33 to $12.94, Research, Estimates), the parent company of CNN/Money, fell more than 3 percent in early trading on the New York Stock Exchange.

News of the CEO search is likely to fuel speculation about the future of Robert Pittman, the media conglomerate's chief operating officer who currently heads the flagging unit.

AOL Time Warner spokeswoman Tricia Primrose said the company hired executive search firm Spencer Stuart to search for a chief executive for AOL.

"We are actively looking for a CEO for the AOL division. That should come as no surprise since when Bob took the post in April, it was always noted an interim job for him," Primrose said. "Bob is and has been the AOL Time Warner chief operating officer and in that regard nothing has changed."

Primrose declined to comment on possible candidates or a time line for the search.

The AOL online unit used to be the jewel in the AOL Time Warner crown. However, the Internet bust and advertising slump have depressed the unit's revenue. That decline has helped AOL Time Warner stock plunge more than 70 percent over the last year. Pittman, who headed the unit prior to AOL's acquisition of Time Warner, was dispatched in April to turn the unit around.

The Wall Street Journal, quoting unnamed sources, suggested Friday there is no guarantee that Pittman will return to his previous duties as chief operating officer once a new AOL leader is named. Pittman once was considered a contender for AOL Time Warner CEO.

But his association with the aggressive AOL culture and overly optimistic revenue projections apparently hurt his standing within the company and on Wall Street. His former co-COO Dick Parsons was named to the CEO job at the beginning of the year.

The Journal reported that no short list of candidates for the AOL online position has been compiled. The search probably will culminate in the selection of an outside candidate, although one insider, Time, Inc.'s Don Logan, also is considered a strong contender.