Helped by a nearly double-digit sales gain, Claire’s Stores Inc. trimmed first-quarter losses by more than half. For the three months ended May 1, the Hoffman Estates, Ill.-based accessories and jewelry retailer recorded a net loss of $12.3 million, down from $29 million in the year-ago quarter. Adjusted earnings before interest, taxes, depreciation and amortization, a non-generally accepted accounting principles measure that strips out numerous onetime charges, as well as interest, taxes, depreciation, amortization and costs related to the 2007 acquisition by Apollo Management LP, rose to $49.2 million from $36.3 million. Earlier, the firm had said it anticipated adjusted EBITDA to land between $47 million and $50 million and reported net sales rose 9.9 percent to $322.1 million from $293.1 million as same-store sales increased 7.6 percent. Gross margin grew to 50.7 percent of sales from 48 percent in the 2009 quarter.