UPDATE 3-Aegis CEO Lerwill to stand down, shares soar

* CEO Lerwill to stand down

* Chairman Napier to take over on interim basis

* Two units 2008 op profits expected in line (Adds details, quotes)

By Kate Holton

LONDON, Nov 27 (Reuters) - Aegis Chief Executive Robert Lerwill is to stand down shortly, the British marketing group said, sending its shares soaring on hopes of strategic change that could allow a deal with French rival Havas (EURC.PA).

Aegis (AEGS.L) has long been seen as a potential target or break-up story and has most recently fought off requests from its biggest shareholder Vincent Bollore -- the chairman of Havas -- for two board seats.

"The market loves restructuring stories. You never know who's going to come in, you never know if it's going to open the door to a merger. Aegis is basically a break-up story anyway," said Alex DeGroote, media analyst at Panmure Gordon.

"There was no management premium for Lerwill. He certainly didn't facilitate a deal with Havas. It may be that the new guy will. I'd be a really, really strong buyer of Aegis on the back of this.

The news of Lerwill's departure sent stock in the media buying and planning group up 16 percent as the firm also said it was trading in line, leaving analysts to guess that there could have been a clash over the company's direction.

The company said Chairman John Napier, who took up the role in July this year, would take on Lerwill's responsibilities on an interim basis. An industry source told Reuters the group was not immediately looking for a new CEO.

The Bollore group declined to comment on the developments on Thursday.

Shares in Aegis had more than halved in value from the start of September to Wednesday's close, compared with a 23 percent drop in the DJ Stoxx European media index .SXMP.

Napier said in the Aegis statement: "The strength of Aegis is the performance of its two large international businesses: Aegis Media and Synovate."

"They are both well-managed and we expect their combined 2008 operating results to be broadly in line with the average of current market expectations."

Analysts at UBS said the reference to the two main units being well managed and the fact their combined 2008 operating results were expected to be broadly in line with forecasts implied a disagreement over strategy.

"The focus now for investors is likely to be on Aegis' strategy going forward and the potential for corporate activity/consolidation in the sector involving Aegis, particularly given the recent share price weakness and the statement's repeated reference to Aegis Media and Synovate as two separate companies," UBS said in a note.

Lerwill became group CEO in early 2005, and the short statement said he would step down at the end of the month.

"I have enjoyed my time at Aegis," Lerwill said. "I leave the group in good hands, with a strong management team capable of meeting the demands of the future. I wish them every success." (Reporting by Kate Holton, additional reporting by Georgina Prodhan in London and Dominique Vidalon in Paris; Editing by Rupert Winchester)