Oil prices slid today, extending last week's sharp decline as the dollar strengthens on euro zone strains and record supplies in the US add further downward pressure. 

US benchmark West Texas Intermediate (WTI) for delivery in April shed $1.17 to $49.64 a barrel compared with Friday's close. 

Brent North Sea crude for April lost $1.24 to stand at $58.98 in London deals. WTI had slumped 4.66% and Brent tumbled 2.1% during the week to last Friday. 

Globally, crude supplies are being boosted after oil fields in eastern Libya resumed pumping to the Hariga port after a pipeline was repaired, Bloomberg News reported. 

Oman, the biggest Middle East producer outside the Organisation of Petroleum Exporting Countries, plans to ramp up output to 980,000 barrels a day this year. 

Crude prices lost around 60% of their value between June and late January due to an oversupply in world markets, a weak global economy and a strong dollar that made oil expensive to purchase for holders of rival currencies. 

The euro continued to be pressured by the dollar today despite euro zone ministers tentatively agreeing to extend Greece's bailout by four months. 

While oil prices have won support in recent weeks on a decline in operating US oil rigs and as energy giants cut investment, markets-watchers say volatility is likely to continue for some time. 

Analysts said a sustained rebound for oil prices was unlikely because of a global oversupply of the commodity, noting that US crude production has remained strong at above 9.2 million barrels per day. 

They said a strike in US oil refineries has led to an excess of crude in the American market as less of the product is being sent to the facilities for refining. 

Workers at three major US oil refineries operated with Royal Dutch Shell went on strike on Saturday in a dispute over safer working conditions, the United Steelworkers (USW) union said. 

About 1,350 employees in three refineries and chemical plants are affected by the latest strike action, which mirrored walkouts on other sites launched earlier this month.