Investors shot down shares of Big 5 Sporting Goods Corp. last week as weak gun and ammunition sales were a drag on earnings, even as it posted numbers that met analysts’ expectations.

The El Segundo retailer reported net income of $2.1 million (9 cents a share) for the quarter ended March 31, down from $7.5 million (34 cents) the same period a year earlier. Revenue fell 6 percent to $231 million.

Analysts had expected the earnings of 9 cents a share, but investors nevertheless fled, sending shares down 21 percent to close at $12.21 for the week ended April 30, landing Big 5 among the biggest losers on the LABJ Stock Index. (See page 40.) The company issued second quarter earnings guidance of low single digits, either negative or positive, which was lower than past guidance.

Steven Miller, Big 5’s chief executive, cited weak gun sales as well as poor performance in winter-related items because of the warmer weather that hit the company’s western market.

“Sales in the second quarter to date have been challenged by lower than expected demand for firearms and ammunition products compared to the prior year,” he said in a statement accompanying the quarterly report. “That being said, we feel well-positioned from a merchandise and promotional perspective for the key selling period during the quarter, which includes Memorial Day, Father’s Day and the start of the summer season.”

Gun sales were brisk nationwide last year because of fears of more restrictive gun regulations.

Sean McGowan, analyst at Needham & Co. Inc. in New York, said there was no surprise in the company’s weak numbers, but said hints of further decline drove the market’s negative reaction.

“It was the profit guidance for the second quarter that was pretty disappointing,” said McGowan. “The last conference call that they hosted indicated some confidence that business would pick up enough in the second half that they would be able to show positive same-store sales increases for the full year, but on this last call they did not express that confidence.”

McGowan said he expected Big 5 would recover, even if at a slower pace, and that he had raised his full-year earnings per share estimate to $1.50 from $1.30.

Big 5, which has about 9,000 employees, operates 425 stores in 12 Western states. It plans to open an estimated 12 to 15 stores this year.

Its competitors include La Canada-Flintridge’s Sport Chalet Inc.; Dick’s Sporting Goods Inc. of Coraopolis, Penn.; and Sports Authority Inc. of Englewood, Colo.