As Oil Industry Fights a Tax, It Reaps Billions From Subsidies

By DAVID KOCIENIEWSKI

When the Deepwater Horizon drilling platform set off the worst oil spill at sea in American history, it was flying the flag of the Marshall Islands. Registering there allowed the rig’s owner to significantly reduce its American taxes.

The owner, Transocean, moved its corporate headquarters from Houston to the Cayman Islands in 1999 and then to Switzerland in 2008, maneuvers that also helped it avoid taxes.

At the same time, BP was reaping sizable tax benefits from leasing the rig. According to a letter sent in June to the Senate Finance Committee, the company used a tax break for the oil industry to write off 70 percent of the rent for Deepwater Horizon — a deduction of more than $225,000 a day since the lease began.