Sept 27 (Reuters) - London"s FTSE 100 ended higher on Monday, helped by gains in heavyweight energy and banking stocks, while Rolls-Royce topped the blue-chip index after it agreed to sell its Spanish unit ITP Aero for 1.7 billion euros. The FTSE 100 (.FTSE) advanced 0.2% with the energy (.FTNMX601010) and banking (.FTNMX301010) sectors leading the gains. BP (BP.L) rose 3.1% after saying that nearly a third of its British petrol stations had run out of the two main grades of fuel as panic buying forced the government to suspend competition laws and allow firms to work together to ease shortages. read more Banks HSBC Holdings (HSBA.L), Barclays (BARC.L), Virgin Money UK (VMUK.L) and Standard Chartered (STAN.L) gained between 1.5% and 4%, tracking higher benchmark bond yields . Yields are trading at their highest level since May 2019, suggesting rising inflation pressures. "The fact that the economic picture is becoming an awful lot more difficult doesn"t really bear any relation to what stock markets are doing," said Michael Hewson, chief market analyst at CMC Markets UK. "The stock market works on the basis of liquidity and at the moment (there is) plenty of it." The FTSE 100 has risen about 9.4% so far this year on support from easy central bank policies and re-opening optimism. But the pace of the rise has been slowed recently by inflation risks sparked by higher energy costs and supply chain disruptions. The domestically focussed mid-cap index (.FTMC) rose 0.1%, with travel and leisure stocks (.FTNMX405010) among top gainers. Rolls-Royce (RR.L) gained 10.3% after it said it had agreed to sell its Spanish unit ITP Aero to a consortium led by Bain Capital Private Equity for 1.7 billion euros ($2 billion). The company also won a contest to provide engines for the U.S. Air Force B-52 Stratofortress bombers. read more Hikma Pharmaceuticals (HIK.L) added 1.3% after saying it would buy U.S.-based sterile injectables company Custopharm in a $375 million deal. read more Britain"s United Utilities (UU.L) slipped 1.4% despite forecasting higher revenue and profit for the first half.