By Mohammed Abbas and Anna Driver

MANAMA/HOUSTON (Reuters) - U.S. oil services firm Halliburton Co. is moving its headquarters and chief executive to Dubai to better position itself to gain contracts in the oil-rich Middle East.

Texas-based Halliburton, which was led by U.S. Vice President Dick Cheney from 1995-2000, did not specify what, if any, tax implications the move might entail. It plans to list on a Middle East bourse once it moves to Dubai -- a booming commercial centre in the Gulf.

"My office will be in Dubai, and I will run our entire worldwide operations from that office," said Chief Executive David Lesar at an energy conference in Bahrain on Sunday. "Dubai is a great business centre."

Halliburton has drawn scrutiny from auditors, congressional Democrats and the Justice Department for the quality and pricing of its KBR Inc. unit's work for the U.S. army in Iraq.

The Dubai move drew political condemnation.

"This is an insult to the U.S. soldiers and taxpayers who paid the tab for their no-bid contracts and endured their overcharges for all these years," said judiciary committee chairman Sen. Patrick Leahy, a Vermont Democrat.

Rep. Henry Waxman, chairman of the House Oversight and Government Reform Committee, might hold a hearing on the implications, an aide to Waxman said.

Halliburton, which has long been involved in the Middle East, generated more than 38 percent of its $13 billion (6.7 billion pounds) in oil services revenue in the eastern hemisphere last year.