BP chief Tony Hayward to testify before Congress

NEW YORK (CNNMoney.com) -- Battered BP CEO, Tony Hayward, has been summoned to testify before U.S. lawmakers next week, according to a letter released Tuesday.

The Committee on Energy and Commerce said it will hold a hearing on June 17 as part of an ongoing investigation into the causes of the explosion on the Deepwater Horizon drilling rig that killed 11 people and has spilled millions of gallons of crude into the Gulf of Mexico.

A spokesman for BP on Tuesday confirmed that Hayward will testify.

In the letter, Subcommittee on Oversight and Investigations co-chairmen, Rep. Bart Stupak, D-Mich. and Rep. Henry Waxman, D-Calif. urged Hayward to come prepared, accompanied by someone with "sufficient knowledge" to answer tough technical questions.

"The Subcommittee anticipates that its members may have questions requiring technical knowledge of the Deepwater Horizon rig operations, well design, and safety measures," they wrote.

Since the April 20 explosion, BP has spent over $1 billion related to the spill, a figure that includes payments to individuals and businesses put out of work because of the incident. But estimates for the ultimate cost range from $3 billion to $40 billion, to be paid out over a number of years.

BP found itself in more hot water last week, as some called on the company to suspend its dividend, saying the money should first go to clean-up efforts and damages.

In a meeting with investors Friday, Hayward tried to reassure both the public and BP's shareholders that the company had the money necessary to restore the Gulf Coast and pay for "other things."

"BP faces this situation as a strong company," said Hayward. "We will stand behind all our commitments."

--Senior writer Steve Hargreaves contributed to this report.