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LOS ANGELES, July 1 (Reuters) - Congressman Henry Waxman, the powerful chairman of the U.S. House of Representatives Energy and Commerce Committee, has been hospitalized in Los Angeles after fainting in his district office, a spokeswoman said on Wednesday.

The 69-year-old veteran Democrat from Southern California collapsed on Tuesday, four days after spearheading House passage of landmark climate change legislation that was a major priority for President Barack Obama.

Waxman was chief sponsor of the bill, which bears his name and is designed to slash industrial air pollution blamed for global warming.

Waxman was not feeling well on Tuesday and after fainting was admitted to hospital for "routine testing," said a spokeswoman, Karen Lightfoot.

"He is feeling fine today and is in good spirits," she said in a brief statement.

Waxman, elected to Congress in 1974, took over this year as chairman of the House Energy and Commerce Committee, which has jurisdiction over major environmental and energy legislation. (Reporting by Laura Isensee; Editing by Steve Gorman and John O'Callaghan)