The US Justice Department has agreed to turn over at least 100 scientific documents that BP suspects could show that the US government overestimated the amount of oil that spewed into the Gulf of Mexico from the company's Macondo well.
In a court filing, Justice Department lawyers also vow to work with BP to resolve their dispute over the company's claims that the government improperly withheld thousands of similar documents.
Last month BP asked a magistrate to order the government to turn over more than 10,000 documents that appear to relate to "flow rate issues" following the 2010 Deepwater Horizon spill.
The government estimates 4.9 million barrels of oil spewed from the well, but the company says the government's earlier estimates may have been lower. BP faces penalties based on how much oil spilled.