Ed Grier, 54, started his 28-year Disney career as a senior auditor. From 2004 to 2006, he was executive director of the Disney attractions in Tokyo. In 2006, he took over as head of the Anaheim operations.

Grier oversees a workforce of 20,000 employees at the 506-acre resort, which includes Disneyland, Disney's California Adventure Park, the Disneyland Hotel, Disney's Grand Californian Hotel & Spa, the Paradise Pier Hotel and Downtown Disney.

He came onboard after the opening of California Adventure, an expansion of Disneyland that has struggled to draw the crowds expected by Disney executives. But he won't be around to manage the $1-billion expansion of California Adventure beginning next spring.

A successor hasn't been named.

In an e-mail to Disney staff, Al Weiss, Grier's boss and head of Disney's worldwide park operations, said Grier planned to help his sons operate a postproduction film business in Orange. Grier, who leaves the company Friday, issued his own e-mail to Disney employees, but did not say why he was retiring or what he planned to do next.

"I have had a long and rewarding career with the Walt Disney company, and am excited to explore what's next," he said in the e-mail.