Updated: 12:06 p.m.

The chief executive of Exxon Mobil on Tuesday sought to distance the oil industry from the BP spill that has threatened the future of offshore drilling.

Rex Tillerson, chairman and CEO of Exxon Mobil, told a House panel that an impartial approach was needed to investigate the spill “because this incident represents a dramatic departure from the industry norm in deepwater drilling.”

“We need to know if the levels of risk taken went beyond industry norms,” Tillerson told the Energy and Commerce Subcommittee on Energy and Environment.

Meanwhile, Lamar McKay, president of BP America, told the panel he could not commit to an escrow fund that President Barack Obama and others say is needed to pay claims.

Tillerson was joined by executives from Chevron, ConocoPhillips and Shell as well as BP in appearing before the subcommittee. It was the first time the other oil giant chiefs had publicly addressed questions about the spill.

Other oil executives said that in the aftermath of the spill they had immediately reviewed their safety practices and drilling procedures.

Committee Democrats, however, sought to link the other oil companies to the spill.

Energy and Commerce Chairman Henry Waxman noted that all the major oil companies had the same written response plans as BP.

“What they show is that Exxon Mobil Chevron, ConocoPhillips and Shell are no better prepared to deal with a major oil spill than BP,” the California Democrat said. “The same company — the Response Group — wrote the five plans and described them as ‘cookie-cutter’ plans. Four of the plans discuss how to protect walruses, but there are no walruses in the Gulf of Mexico.”

Tillerson admitted that it was an “embarrassment” that Exxon, too, included walruses in its response plan for Gulf spills.

Subcommittee Chairman Ed Markey (D-Mass.) repeatedly asked McKay to apologize for underestimating the amount of oil leaking. But McKay said the leak estimates came from the unified command, not BP. Asked by Waxman about BP’s well, Tillerson said, “We would not have drilled the well the way they did.”