Oil companies broadly advanced on Tuesday as crude rebounded, buoyed by speculation that Iran will attend a meeting of Opec producing countries next month. Members of the oil producing cartel are expected to meet to discuss actions to support the crude market, which despite Brent rallying 34 per cent this year remains 57 per cent below a 2014 peak. Brent crude, the global benchmark, reversed earlier losses and rose 1.6 per cent to $49.96 a barrel after Reuters said Iran was “sending positive signals” about supporting joint efforts, citing unnamed sources in Opec and the oil industry. West Texas Intermediate, the US oil marker, advanced 1.5 per cent to $48.10 a barrel. Shares of Chesapeake Energy climbed 6.1 per cent to $6.46, Marathon Oil rose 5.1 per cent to $16.43,Southwestern Energy advanced 4.2 per cent to $14.04 and Anadarko Petroleum gained 3.3 per cent to $56.05.