Mattel Inc. announced Monday that Robert Eckert, its chief executive for 11 years, will retire next month at the end of the holiday selling season.

The El Segundo toy maker said Eckert, 57, will be replaced Jan. 1 by Chief Operating Officer Bryan G. Stockton, 58, who joined the company in 2000. Eckert will remain chairman.

“The board respects Bob’s decision to step back at this time, and wants to recognize the superb job he’s done the past 11 years in building a high performance culture at Mattel and delivering truly superior shareholder returns,” said Christopher Sinclair, the independent presiding director, in a statement. Stockton has “been a key architect behind Mattel’s rapid international growth and has also helped to shape many of the company’s recent growth initiatives.”

Mattel last month reported that its third-quarter net income rose 6 percent, boosted by strong sales of its once faltering Barbie toy franchise and movie tie-ins such as its popular “Cars 2” products.

But the company had some expensive and embarrassing missteps during Eckert’s tenure. Mattel in 2004 sued Van Nuys competitor MGA Entertainment Inc. over ownership of the Bratz dolls, which at the time had been chipping away at Barbie’s popularity. A retrial of that case was settled in MGA’s favor earlier this year, with Mattel in August ordered to pay MGA more than $309 million in damages.

Shares were down 92 cents, or 3 percent, to $27.47 in midday trading on the Nasdaq.