Bedding retailer Mattress Firm said second-quarter sales rose 15.5% and profits shot up 40% as the company continued to expand through acquisitions and new store openings.

Same-store sales, however, slipped 0.3%, and the retailer said the figure likely would be flat for its fiscal year.

Net sales for the quarter ended July 30 were $302.5 million, up from $262 million in the same quarter in 2012.

Net income totaled $14.1 million, or 41 cents per share. That was up from $10.1 million, or 30 cents per share, in the comparable quarter.

The company finished the quarter with 1,121 company-owned stores - a net gain of 25 during the quarter -- and has added 64 stores in the first six months of its fiscal year.

Six-month sales and profit figures were similar. Sales rose 22.6% to $578.5 million and net income was up 31.8% to $26.1 million, or 77 cents per share.

Same-store sales for the six months ended July 30 fell 2.5%.

"Our exciting growth story continued in the second quarter of 2013," said Steve Stagner, president and CEO. "We saw revenues increase by 15% over the prior year to $303 million, which evidences that our growth is outpacing the mattress industry, which has experienced mid-single digit growth during the comparable period."

Stagner said he expects sales and store traffic to improve in the second half of the year as the industry increases its advertising spending.

The company, however, has cut its sales and earnings estimates for its fiscal year, which ends Jan. 28.

Sales are now projected at $1.19 billion to $1.21 billion, down from a March projection of $1.24 billion to $1.25 billion.

The new earnings per share projection is $1.66 to $1.74, down from the March projection of $1.81 to $1.89.

In its last fiscal year, Mattress Firm had sales of $1.007 billion and earnings of $1.18 per share.