WASHINGTON, April 30  A Halliburton executive, facing withering criticism from Democratic lawmakers during a Senate hearing on Monday about the company’s business dealings in Iran, insisted that the firm had not broken any laws.

The official, Sherry Williams, a Halliburton vice president and corporate secretary, said the company had consulted several law firms in 1995 after sanctions were imposed on Iran. Officials of the company, which recently announced it was moving its chief executive from Houston to Dubai and establishing a corporate headquarters there, determined that it was legal for independent foreign subsidiaries of United States companies to do business there, she said.

“We have followed U.S. law,” she said. “We will continue to follow U.S. law.”

Although the three Democratic senators on hand repeatedly suggested broader concerns than strict legality should have prompted the company to halt its business in Iran, Ms. Williams expressed no regret for the firm’s work there.

From 1995 to 2000, Vice President Dick Cheney was Halliburton’s chairman; at the time he spoke out against sanctions on Iran.