SINGAPORE, June 13 (Reuters) - Oil was a touch easier on Friday after a volatile previous session when the market grappled with supply worries in Nigeria, the world's 8th-largest producer, and a firmer U.S. dollar.
U.S. crude oil <CLc1> was off 6 cents at $136.68 a barrel by 0205 GMT, but still within sight of last week's record $139.12.
The contract traded in a near-$6 range on Thursday, ending 36 cents higher at $136.74 a barrel, as concerns mounted about a possible strike in Africa's top oil producer.
London Brent <LCOc1> was up 3 cents at $136.12 a barrel.
Nigeria's senior oil workers' union, which was pushing for the expatriate managing director of Chevron's <CVX.N> local unit to be transferred out of the country, said on Thursday that talks to avert a lockout were not going well and renewed its strike threat. [ID:nL12214153]
"Certainly, we're worried about Nigeria, we're still very mindful of the situation," said Peter McGuire, managing director of Commodity Warrants Australia.
A strike would further dent oil output in Nigeria, where a fifth of capacity has been shut since early 2006, when ethnic militants in the Niger Delta began a violent campaign of sabotage against oil installations.
But U.S. currency gains weighed on oil prices, which have gained more than 40 percent this year as investors played on a weaker dollar and bought commodities to hedge against inflation.
The dollar stayed firm against the euro on Friday, holding on to gains made the previous day after surprisingly strong U.S. retail sales data supported expectations for two or more Federal Reserve interest rate hikes this year. [ID:nT286484]
Later on Friday, traders will watch U.S. consumer price data for May and real earnings for further signs on the economic health of the world's top oil consumer.
The market will also keep an eye on moves by regulators in the United States and Britain to rein in speculative crude futures trading, which OPEC has said is the main cause of the spikes in oil prices. [ID:nN12348691]
Iraqi Oil Minister Hussain al-Shahristani reiterated that view on Thursday, saying more crude from Saudi Arabia or other OPEC producers will not solve the problem of high global prices. [ID:nL12710949] (Reporting by Chua Baizhen, Editing by Ian Geoghegan)
