WASHINGTON -- Sen. Dianne Feinstein, D-Calif., has broken her ankle and will skip next week's Democratic National Convention.

Feinstein, who was one of Hillary Rodham Clinton's top supporters, was to have chaired California's delegation to the convention in Denver.

Feinstein slipped and broke her ankle Friday while taking a walk on Meeks Bay Trail in the Lake Tahoe forest with Rep. Ellen Tauscher, D-Calif., the senator said in a statement Tuesday.

Initially Feinstein thought she'd just sprained her ankle, according to spokesman Scott Gerber. She attended the annual Lake Tahoe Summit on Saturday despite the accident.

Feinstein saw a doctor in San Francisco on Monday and learned that she'd broken her fibula, Gerber said.

"My doctor has advised me not to travel in the short-term, and so, regretfully, I am unable to attend what will surely be an historic convention in Denver," California's senior senator said in a statement.

"I was very much looking forward to chairing the California delegation, and I offer my best wishes to California's delegates in this vital nomination process."

Feinstein was co-host with Gov. Arnold Schwarzenegger of the Tahoe Summit, which focused on environmental and forest health issues. Coincidentally Schwarzenegger did not attend because of a knee injury.

In recent weeks Feinstein, 75, has faced speculation about whether she might run for governor of California in 2010. She's been noncommittal.