BP today clawed back 1.1 billion US dollars (£677 million) from one of its partners on the Deepwater Horizon rig to cover claims related to the Gulf of Mexico oil disaster.
MOEX Offshore, a US subsidiary of Japan's Mitsui Oil Exploration Company, had a 10% interest in the Macondo well at the site of the explosion which killed 11 men and triggered the largest oil spill in US history.
BP said MOEX is the first of its partners to pay towards claims arising from the accident and is working to ensure other parties involved - singling out Transocean, Halliburton and Anadarko - contribute appropriately.
BP, which was chasing MOEX for up to 2.1 billion US dollars (£1.2bn), said the settlement would be immediately paid into the 20bn US dollar (£12.3bn) trust set up to meet compensation claims.
The oil spill on April 20 last year has cost BP 40.9 billion US dollars (£25.5 billion) to date - pushing it to its first annual loss in 20 years in 2010.
The company has paid nearly 6 billion US dollars (£3.7 billion) in claims to individuals, businesses and the US Government, ranging from states, parishes and counties to Indian tribes.
BP said MOEX had recognised findings of the investigation commissioned by President Barack Obama that the incident was down to "separate risk factors, oversights and outright mistakes by multiple parties".
But the British supermajor added the settlement is not an admission of liability by any party regarding the disaster.
Chief executive Bob Dudley said: "This settlement is an important step forward for BP and the Gulf communities.
"MOEX is the first company to join BP in helping to meet our shared responsibilities in the Gulf, and Mitsui, through MOEX USA Corporation, is showing great corporate citizenship in standing behind its affiliate and making a contribution to meet the costs of this tragic accident.
"We call on the other parties involved in the Macondo well to follow the lead of the MOEX and Mitsui parties."
BP has sold 25 billion US dollars (£15 billion) worth of its assets to raise funds to contribute to the disaster and plans to sell further oil and gas fields in the UK and two of its US refineries - Texas City and Carson.
But the company pledged to pursue its other partners for the part they played in the disaster.
Transocean, which owned and operated the Deepwater Horizon rig, Halliburton, which designed and pumped the cement at the base of the well and Anadarko, which owned 25% of the project, are all in BP's sights.