Barbie sales fell 15%.

Shares of toy maker Mattel (MAT 0.67%) plunged more than 10% in pre-market trading, following the release of disappointing second-quarter results.

Net sales of $1.06 billion represented a 9% year-over-year decline. Earnings fell to $0.08 per share, compared to $0.21 per share in the year-ago period. GAAP earnings include a $0.11 tax benefit and a $0.06 MEGA Brands acquisition charge per share. Back these items out and the adjusted figure drops to $0.03 per share.

Analysts were looking for earnings of $0.18 per share on about $1.2 billion in sales. Mattel fell far short of these estimates.

Sales in the Barbie brand category fell 15% year-over-year. Fischer-Price's sales fell 17% and car toys under brands like Matchbox and Hot Wheels fell 3%. The new construction and arts & crafts segment, which was created by April's $423 million MEGA acquisition and includes brands like MEGA Bloks and RoseArt, reported sales of $61.6 million.

A bright spot amid the plunging sales, American Girl brands saw sales rise 6% to $83.1 million.

In a prepared statement, Mattel CEO Bryan Stockton expressed disappointment with second-quarter results, and explained what Mattel is doing to reach a stronger position for the all-important holiday season. "We completed the acquisition of MEGA Brands, reduced inventories, strengthened our management team, shifted marketing spend to the back half of the year, and exercised strong controls on SG&A expenses," Stockton said. "We need to drive [point of sale results] higher by bringing innovative products to market, making additional advertising investments and optimizing the effectiveness of our marketing spend."