May 21 (Reuters) - Off-price retailer Ross Stores Inc (ROST.O) posted a 15 per cent rise in quarterly profit as strong sales and merchandise margins boosted business, and forecast second-quarter earnings above market view, sending its shares up 6 percent.

Ross Stores Spring 2009

"Our business benefited... as we continue to take advantage of the substantial amount of close-out opportunities in the marketplace," Chief Executive Michael Balmuth said in a statement.

The company's low prices for branded merchandise -- from clothes to home goods -- have attracted customers hunting for discounts as they fight the recession.

Net profit for the first quarter was $91.4 million, or 72 cents a share, compared with $79.5 million, or 60 cents a share in the previous year.

Revenue grew 9 percent to $1.69 billion, with comparable store sales rising 3 percent.

Balmuth also said operating margin for the quarter grew about 75 basis points to 8.9 percent, driven by a 90 basis point improvement in gross margins.

For the second quarter, the company expects to earn 60 cents to 63 cents a share. Analysts on average were expecting earnings of 53 cents, according to Reuters Estimates.

The company also said it remained on track to complete the remaining $223 million stock repurchase authorization by the end of fiscal 2009.

Shares of the company were up 6 percent at $38 in trading before the bell on Thursday 21 May. (Reporting by Nivedita Bhattacharjee in Bangalore; Editing by Gopakumar Warrier)