PORTLAND — The widow of the former chairman of Maine Savings Bank has sued the Federal Deposit Insurance Corp., challenging its denial of her claim to her late husband’s $2.34 million retirement package from the failed bank.

Nancy Masterton of Cape Elizabeth filed the suit in U.S. District Court as sole beneficiary of the estate of Robert R. Masterton.

At the time of his death in 1988, Masterton, 58, was chairman and chief executive officer of both The One Bancorp and its principal subsidiary, Maine Savings Bank.

After it was declared insolvent early last year, Maine Savings was closed and placed in receivership under the FDIC.

On April 12, 1991, Mrs. Masterton filed claims with the FDIC of $308,729 under a deferred compensation agreement from 1982 and $2.34 million under a supplemental retirement agreement from 1979.

A year later, the federal agency advised Mrs. Masterton it had allowed the deferred compensation claim but disallowed the claim to the supplemental retirement package.

Mrs. Masterton’s suit challenged the FDIC’s determination, saying it became invalid when The One Bancorp halted payments despite its guarantee to meet the obligations of Maine Savings under the retirement agreement.

The One Bancorp, which moved its headquarters from Portland to Brockton, Mass., following the seizure of Maine Savings, was directed by the FDIC to apply its assets to other troubled banks within its system, said George F. Burns, an attorney for Mrs. Masterton.

The FDIC denied the retirement claim on grounds that Mrs. Masterton failed to establish that she suffered any damage, Burns said. “Because The One Bancorp has stopped making those payments, we are now asking the FDIC to reconsider its decision,” he said.

In its role as receiver, the FDIC has broad powers to repudiate contracts for executive compensation it concludes are excessive, said an FDIC lawyer in Washington who was not familiar with the Masterton case and did not want to be quoted by name.

Masterton, a key figure in Portland’s economic revival, engineered Maine Savings’ pioneering conversion from a staid mutually owned thrift institution to a stock company that went on to become an aggressive lender to commercial real estate developers.

In the process, the assets of the 130-year-old bank soared to more than $2 billion. But the collapse of the New England real estate market left the bank insolvent and it was absorbed by Fleet Financial Group in a federally assisted takeover.