British energy giant BP on Tuesday posted the company's biggest loss in at least 20 years, ravaged by tumbling oil prices, and axed another 3,000 jobs.

BP suffered a loss after taxation of $6.48 billion (5.97 billion euros) last year, compared with a net profit of $3.78 billion in 2014, it said in a results statement.

The energy major added it would slash 3,000 positions in its downstream business -- including refining, marketing and distribution -- by the end of 2017.

Earnings were hit by a $2.6-billion charge in the fourth quarter that was mostly linked to impairments in the upstream division, or exploration and production, as well as restructuring costs.

The company took another $12-billion hit for the Gulf of Mexico oil spill, taking its total bill for the tragedy to $55.5 billion.

BP added that underlying replacement-cost profit -- which excludes fluctuations in the value of crude oil inventories -- more than halved to $5.9 billion last year.

The earnings measure tumbled to just $196 million in the fourth quarter, from $2.2 billion a year earlier.

‘The lower underlying result was predominantly driven by the impact of steeply lower oil and gas prices on BP's upstream segment,’ the company said.

In late morning deals, BP's share price tanked 8.26 percent to 336.60 pence on the London stock market, which sank 1.72 percent in a global selloff.

‘Sustained low prices have seen BP post their worst annual loss in 20 years as the company looks to cut more jobs in order to cut costs and fight back towards profitability,’ noted GKFX analyst James Hughes.

Rival energy major Royal Dutch Shell, which reports its annual earnings on Thursday, saw its 'A' share price slide 3.33 percent to 1,450 pence.

Oil prices have crashed about 75 percent since mid-2014, hit by the slowing global economy, the strong US dollar -- and a chronic supply glut that has been exacerbated by OPEC's refusal to curb crude output.

The energy sector has meanwhile slashed jobs and investment in response to the oil price collapse.

BP had already announced plans last year to axe 4,000 jobs in its upstream division in a radical restructuring of the company.

The latest job cuts take its total cull to 11,000 positions since the start of 2015.

‘We are continuing to move rapidly to adapt and rebalance BP for the changing environment,’ said chief executive Bob Dudley.

‘We're making good progress in managing and lowering our costs and capital spending, while maintaining safe and reliable operations and continuing disciplined investment into the future of our portfolio.’

BP added Tuesday that it has now completed its $10-billion asset sale programme that was announced in October 2013, and plans to sell a further $3-5 billion of assets this year.

World oil prices had nosedived last month to 12-year lows underneath $27 dollars per barrel, having peaked in the summer of 2014 at about $115.