A company document has indicated that BP elected to use a casing on the Gulf of Mexico well that exploded last month that carried more risk than other types of casings.

The document, obtained by The New York Times, has indicated that days before the April 20 explosion on the Deepwater Horizon oil rig, officials, choosing between two options, decided to use a casing that could allow gases from the well to leak as far as the wellhead.

It obtained the document from a congressional investigator, the newspaper reported on Thursday.

The Times has reported that BP officials based the decision in part on cost considerations. BP spokesman Andrew Gowers told the newspaper the company's choice was not out of the ordinary.

Gowers said, "BP engineers evaluate various factors for each well to determine the most appropriate casing strategy."

However, the decision was "without a doubt a riskier way to go," Greg McCormack, who heads the Petroleum Extension Service at the University of Texas at Austin, told the newspaper.

The Times further said that the U. S. Coast Guard and the Interior Department's Minerals Management Service opened hearings Wednesday in Kenner, La., to look into what impact financial and time pressure may have had on the Deepwater Horizon operation.

He saw crew members arguing with a BP worker the day of the explosion in a disagreement over the company's decision to replace heavy drilling fluid with lighter saltwater before sealing the well with a cement plug, The chief mechanic on the Deepwater Horizon, Douglas H. Brown, has testified.

It was further reported that BP executives are scheduled to testify Thursday before the House Committee on Natural Resources. (With Inputs from Agencies)