EL SEGUNDO, Calif.–Mattel Inc. Chief Executive Officer Robert A. Eckert will retire on Dec. 31 and be replaced by Chief Operating Officer Bryan G. Stockton, the world’s biggest toymaker announced today.

A statement said Eckert, 57, had informed the Mattel board of his decision to leave the job after 11 years with the company. But he will become non-executive chairman of the board.

Stockton, 58, who has been COO for the past year, has been elected to the board, the statement said.

“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. He leaves behind a remarkable legacy of integrity and success,” said Christopher A. Sinclair, independent presiding director for Mattel.

“We’re also grateful that Bob has agreed to serve as non-executive Chairman and support Bryan in a seamless transition. Finally, we are delighted to have an experienced and proven leader like Bryan assume the CEO position. He’s been a key architect behind Mattel’s rapid international growth …”

Mattel said that through year-end 2010, the company generated $8.2 billion in cash, which it used to strengthen the balance sheet and return about $4.6 billion to shareholders in the form of dividends and share repurchases.

“Simply stated, I have loved working at Mattel, and it has been my privilege to work alongside the most talented and dedicated people in the toy business,” Eckert said.

Stockton expressed gratitude “for this incredible opportunity to advance the Mattel legacy. And on behalf of the 30,000 employees of Mattel, I want to thank Bob for his 11 years of leadership marked by financial discipline, global expansion and a commitment to employee development.”