Republican presidential hopeful Rudy Giuliani's law firm lobbies for Citgo Petroleum Corp., which is controlled by the Venezuelan state oil company and President Hugo Chavez, but the firm said on Wednesday that Giuliani has never worked on the account.

The leftist Chavez is an ardent foe of President George W. Bush's administration and a bane to conservatives whose support Giuliani will need as he seeks the 2008 Republican presidential nomination.

Records filed at the Texas Ethics Commission showed the law firm, Houston-based Bracewell & Giuliani, may have received up to $170,000 from Citgo since 2005.

A spokeswoman for Giuliani's campaign, which has been buoyed by recent opinion polls showing him leading his Republican rivals, declined to answer questions, but provided an e-mail statement denouncing Chavez.

"Mayor Giuliani believes Hugo Chavez is not a friend of the United States and his influence continues to grow because of our increasing reliance on foreign sources of oil," the statement read.

It concluded with a call for developing alternative sources of fuel to replace foreign crude oil. Venezuela is the No. 4 oil supplier to the United States.