State-owned Arab company Dubai Ports World has pledged to transfer operation of six US port terminals to a US entity in a move the White House said should settle controversy over the deal.
But the US Congress was sceptical. Many lawmakers have demanded the Dubai company be stopped from running the ports because of potential security risks.
The issue has sparked a rebellion against President Bush, whose administration approved the company's involvement in January, within his own Republican Party.
The statement by Dubai Ports World's chief operating officer, Edward Bilkey, announcing the transfer to a US entity was read out on the Senate floor by Virginia Republican John Warner.
But Capitol Hill critics in both parties said they wanted to see the fine print before backing away from legislation to unwind the contract, noting the company had not said to whom it was selling, or when.
One House Republican leadership aide said that because of the company's announcement, there could be a motion to strike the language reversing the deal in the House next week - but noted this would still require a vote.
In Dubai, sources close to the deal said the United Arab Emirates government had intervened to defuse the crisis that exploded in Washington last month after the deal became known.
The ports dispute, which played into American concerns about security since the September 11th attacks, proved a political hot potato for the Republicans seven months before elections in which Democrats hope to regain control of Congress.