UPDATE 4-US House panel to subpoena Fed over BofA-Merrill

* House panel says to subpoena Fed for B of A documents

* Lawmakers say is third time they have sought information

* Say Fed would not let them have copies of documents

* CEO Lewis: Fed, Treasury asked for delay in reporting (Adds Lewis testimony, details)

By Kim Dixon

WASHINGTON, June 9 (Reuters) - A House of Representatives committee on Tuesday said it would subpoena the Federal Reserve to force the central bank to surrender documents regarding its role in Bank of America's (BAC.N) takeover of Merrill Lynch last year.

The subpoena comes two days before Bank of America Chief Executive Ken Lewis is set to testify before the House Oversight Committee, which is probing the transaction, what Lewis knew about Merrill's financial condition and potential regulatory pressure to complete the deal.

Lewis, in testimony prepared for the hearing, said he became aware of "significant, accelerating losses" at Merrill in mid-December after the shareholder vote. Lewis has consistently maintained in statements that he did not realize the severity of Merrill's problems until after that vote.

The CEO, who has since been ousted as chairman, also said he told Treasury and Fed officials he was considering declaring a "material adverse change" which would have allowed it to walk away from the acquisition.