May 26 (Reuters) - Weak trends at American Eagle Outfitters (AEO.N) prompted the company to forecast a second quarter that fell way below expectations, sending its shares down 10 percent on Wednesday 26 May.

American Eagle Outfitters Women's Beachwear Spring-Summer 2009

The company, owner of the American Eagle, aerie and 77kids by American Eagle brands, has been losing market share to lower priced rivals like Aeropostale Inc (ARO.N) and privately held Forever 21, despite adding more fashion items to its assortment while controlling discounts.

For the second quarter, American Eagle forecast a loss of 1 cent a share to a profit of 3 cents a share, below analysts estimates of a profit of 21 cents a share, according to Thomson Reuters I/B/E/S,

The second-quarter view reflects "margin pressure related to weaker business trends early in the quarter," the company said.

During the quarter, total merchandise inventory for the company that has leaned heavily on denims to attract girls, was $326 million, an increase of $47 million.

However, on a conference call with analysts, the company said it was planning to cut down inventory in the second half of the year, as it looks to manage pricing and units better. American Eagle's net profit in the first quarter ended May 1 was $10.9 million, or 5 cents per share, from $22 million, or 11 cents per share, a year earlier.

Excluding costs associated with the exit from its profit-losing Martin + Osa chain earlier this year, the company earned 17 cents a share, in line with analysts average estimates of 17 cents a share.

Revenue rose 8 percent to $659.5 million. Analysts were looking at revenue of $656.3 million.

Shares of the Pittsburgh-based company were down at $13.87 Wednesday 26 May, making them the biggest percentage loser on the New York Stock Exchange. (Reporting by Nivedita Bhattacharjee in Bangalore; Editing by Aradhana Aravindan)