Executives of the biggest oil companies are taking their case for expanded offshore drilling to Congress, even as Democratic congressional leaders and the Obama administration promise to put some limits on energy development along the nation's coasts.
The executives were testifying Wednesday before the House Natural Resources Committee.
The panel previously heard from opponents to drilling and from officials representing the governors from a number of coastal states.
Committee Chairman Nick Rahall, D-W.Va., said he's not opposed to offshore drilling, but was holding the hearings to learn more about "the trade-offs that would be involved" if more coastal waters were opened to oil and gas companies.
Congress last October ended the long-standing ban on drilling in about 85 percent of the country's coastal waters, from New England to the Pacific Northwest.
Environmentalists have called for the ban to be re-imposed.
The oil executives to testify are Larry Nichols, chairman of Devon Energy ; Marvin Odum, president of Shell Oil; Lamar McKay, president of BP America; and the top executives of the exploration and production arms of Exxon Mobil and Chevron .
In a conference call Tuesday with reporters, Nichols said the message he and the other executives want Congress to hear is that "for decades to come the vast majority of our energy is going to come from our historic sources, mainly oil and natural gas," and there are substantial resources in federal coastal waters.
Also Tuesday, officials from several coastal states told the committee that states' views must be taken into account before the federal government allows oil drilling in federal offshore waters.
And some states made clear they want no drilling -- period.