NEW YORK -- MetLife said it has failed to pay some retirees for more than two decades. 

The company said it owes customers for annuity payments going back about 25 years. An annuity is a fixed sum of money paid to someone each year, typically for the rest of his or her life. MetLife said in an internal review, nearly 14,000 people were owed payments they never received.

The company adds it did not make an appropriate effort to contact the recipients before writing them off as undeliverable. MetLife said it will set aside more than $500 million to make the payments.