* Sees 2013 operating profit 510-530 mln euros
* Analysts had forecast 2013 operating profit at 535 mln
* CFO says July-Sept bookings "good"
* H1 operating profit falls 6.4 pct
* Shares down 4.8 pct, profit outlook disappoints
By Dominique Vidalon
PARIS, Aug 28 (Reuters) - Accor, Europe's largest hotel group by sales, warned operating profit could fall this year due to the weak economy in its main market and investment in an online booking service to compete with rivals like Expedia.
The French company - which appointed private equity specialist Sebastien Bazin as chairman and chief executive on Tuesday - gave no clues about his strategy plans, disappointing investors.
Analysts have said they expect Bazin to speed Accor's shift towards franchising or managing hotels for others rather than owning them, to boost profit margins and cut net debt of 581 million euros ($778 million) at the end of June.
Accor, which competes with InterContinental, Marriott and Starwood, is in the first year of a three-year plan to lift its operating margin to more than 15 percent of sales in 2016 from 9.3 percent in 2012.
Chief Financial Officer Sophie Stabile, who stood in for Bazin on a conference call with analysts on Wednesday, said it was too early to say whether the plan, which includes asset sales and cost cuts, will be reviewed.
"We will probably come back to you by the end of the year" Stabile said.
By 1136 GMT, Accor shares were down 4.8 percent, leading decliners on the CAC-40 index of French blue-chip stocks .
Europe's largest hotel group makes more than 70 percent of its sales in the region, which is just emerging from recession, and is more exposed to the weak economy than rivals. In response, it is cutting costs and accelerating its expansion in faster-growing emerging markets.
Bazin, who ran European operations for Accor's largest shareholder Colony Capital, became vice-chairman in April after the company ousted chairman and chief executive Denis Hennequin.
Accor forecast 2013 operating profit of 510 million to 530 million euros on Wednesday against the 526 million made in 2012.
This was below the average estimate of 535 million euros ($717 million) in a Thomson Reuters I/B/E/S poll of analysts.
"Accor's guidance is at the lower end of the consensus range and a few questions remain open with regard to the (strategy) plan," said Societe Generale analysts in a note to clients.
Stabile said summer business was robust and the trend should continue in the second half.
However, investments to bolster Accor's online sales, which contributed to a 6.4 percent fall in like-for-like operating profit in the first half, would continue to weigh.
Stabile said these investments were around 20 million euros in the first half and should be of the same order for the second.