Here are some developments in BP's Gulf of Mexico oil spill, the largest offshore oil disaster in U.S. history.

Top Developments
• BP fine-tuned its equipment on Tuesday to deliver the first of two planned kills to permanently plug its ruptured Gulf of Mexico oil well that caused the world's worst accidental oil spill.

Market Impact/Companies
• Baker Hughes, the third-largest U.S.-listed oilfield services company, said the Gulf of Mexico deepwater drilling moratorium hurt its second-quarter profit and will also cut into earnings in the second half of the year.

• Japanese trading house Mitsui said BP has sent it a $480 million bill seeking help in the cleanup of the disastrous Gulf of Mexico oil spill, but it has not decided if it will shoulder any costs.

• BP said it would sell its Colombian assets to a consortium of Canada's Talisman Energy and Colombia's state-run Ecopetrol for $1.9 billion.

• State-run Kuwait Petroleum International may be interested in buying some of BP's assets, the country's oil minister told journalists in Moscow on Tuesday, after meeting with Russia's Energy Minister.

• BP shares rose .62% in London and shares in New York were up about 1.4% on Tuesday.

Politics/Policy
• Senate Majority Leader Harry Reid is delaying action on energy legislation that would implement offshore drilling reforms until sometime after Congress returns from its summer recess in mid-September, Democratic Senator Dianne Feinstein said on Tuesday.

Capture/Containment/Cleanup
• BP said it began a critical test at its blown-out Gulf of Mexico oil well on Tuesday afternoon in advance of a "static kill" intended to help permanently kill the leak.

Environment
• Dispersant chemicals used to break up oil from the BP spill are generally less toxic to test species than oil alone, U.S. Environmental Protection Agency data released on Monday showed.

• This year's low-oxygen "dead zone" in the Gulf of Mexico is one of the largest ever, about the size of Massachusetts, and overlaps areas hit by oil from BP's broken Macondo well, Louisiana scientists report.