LONDON (AFP) - Crude oil prices rose slightly on Thursday as US lawmakers scrambled for a compromise to avert a devastating debt default for the worlds biggest economy, analysts said. New Yorks main contract, light sweet crude for delivery in September, gained 10 cents to $98.50 a barrel. Brent North Sea crude for September climbed 46 cents to $117.89 in London deals. A drawn-out political impasse in the United States, as polarised politicians struggle to find a middle ground over a debt solution for the worlds largest oil consumer, was exacting its toll on traders. The United States is the worlds biggest consumer of oil. Some market talk that a deal on the US debt ceiling may be hammered out had offered some better (oil price) sentiment but there is no confirmation yet, said Brenda Sullivan, an analyst at brokerage Sucden Financial. Congress was due later Thursday to consider Republican Speaker John Boehners plan to raise Washingtons $14.3 trillion debt ceiling, although it looked doomed to fail due to a White House veto threat. US lawmakers were privately hunting for a compromise to avert a debt default due to kick in on August 2.