UK stocks opened flat on Tuesday as continued political turmoil in Saudi Arabia continued to boost oil plays.
At 0857, the benchmark FTSE 100 index was down 0.86 of a point at 7,561.42.
Shell and BP added 0.9% and 0.7%, respectively.
Smaller energy companies continued to enjoy strong gains, with Tullow Oil, Ophir Energy and Premier Oil up 4.6%, 3.5% and 3.0%, respectively.
Associated British Foods boosted annual pre-tax profits by 22%, but revenue growth at retail chain Primark slightly missed company guidance, sending its shares 3.5% lower.
Cigarrette maker Imperial Brands rose 2.4% after favourable currency movements helped it boost annual revenue and profits.
Security firm G4S was one of the morning's biggest fallers, losing 5.4% after it said it expects to post full-year organic revenue growth of 3-4% and "good" profit growth.
Building products supplier Tyman shed 4.8% after forecasting an underlying annual pre-tax profit slightly below the current range of analyst expectations.
Direct Line Insurance added 0.2% after announcing that it remains on track to meet its targets.
Hiscox, meanwhile, saw gross written premiums rise by 12.4% in the first nine months of the year. Its shares gained 0.4%.