By Shadia Nasralla LONDON (Reuters) – Oil prices climbed to almost $120 a barrel on Thursday, their highest in nearly a decade, as sanctions disrupted Russian oil sales but the rally lost some of its fizz on rising prospects for an Iran nuclear deal that could add extra supplies. Benchmark Brent rose to $119.84 a barrel, the highest since 2012, with additional support coming from data showing U.S. crude stockpiles had hit multi-year lows. By 1416 GMT, it had slipped back to $112.75 a barrel. Brent has jumped by more than a third in the past month. The contract’s six-month spread hit a record h…