* European shares rebound after by BoE minutes shock, BoA earnings * Bernanke's testimony starts at 1400 GMT, prepared remarks at 1230 GMT * Dollar steady after coming off three-week low * Commodity markets in holding pattern ahead of Fed By Marc Jones LONDON, July 17 (Reuters) - The dollar dipped back towards a three-week low and European stocks and benchmark bonds gained on Wednesday, after the head of the Federal Reserve said plans to scale bank U.S. monetary stimulus were not set in stone. "Our asset purchases depend on economic and financial developments, but they are by no means on a pre-set course," the U.S. central bank's chairman Ben Bernanke told a U.S. House of Representatives committee in prepared remarks. The comments were broadly in line with analysts' expectations but were enough to evoke a reaction in markets that had become tightly positioned ahead of the release. U.S. Treasury yields eased three basis points to 2.52 percent. The dollar index was down 0.1 percent at 82.43, with the euro cutting earlier losses to hit a session high of $1.31795. Sterling also extended gains against the dollar to hit a two-week high of $1.5270. Bernanke's comments followed the surprising news that there were no calls for fresh stimulus at Mark Carney's first meeting in charge of the Bank of England. "We have seen a bit of a drop in yields and euro/dollar is a bit higher so maybe it was a little dovish. But there was never going to be much excitement in the prepared remarks, it is really about the question-and-answer session," said Peter de Bruin a senior economist at Rabobank. "I think Bernanke will try not to come up with any new surprises ... He has done his utmost to pour cold water on interest rate hike expectations so I suspect a similar tone." Bernanke's semi-annual statement to Congress, which may be his last if the chairman steps down when his term ends in January, as many expect, will be followed by a lengthy question-and-answer session with the committee's members. The broad FTSEurofirst 300 was up 0.8 percent at 1300 GMT having been up 0.4 percent before Bernanke's comments. U.S. stock futures also extended their gains, while Brent oil gained around 30 cents to $108.30 a barrel.