Rite Aid Corp posted a worse-than-expected quarterly loss on weak sales from a mild winter cold and flu season, and lower profits on generic drugs and reimbursement rates. It was the drugstore chain's 11th straight quarterly loss.

The loss narrowed to $208.4 million, or 24 cents per shares, in the fourth quarter ended on February 27 from $2.29 billion, or $2.67 per share, a year earlier.

Analysts on average had forecast a loss of 19 cents a share, according to Thomson Reuters I/B/E/S.

Sales fell 3.6 percent to $6.46 billion.

Rite Aid forecast a fiscal 2011 loss per share of between 41 cents and 65 cents, while analysts expect a loss of 36 cents.

(Reporting by Phil Wahba; additional reporting by Jessica Wohl; Editing by Lisa Von Ahn)