The letters for "MassMutual" are being taken off Tower Square in Springfield.
Insurance company officials say the letters are being removed because MassMutual no longer owns the downtown skyscraper, although it will still have offices in the building.
MassMutual sold the building to an investor group earlier this year.
The new owners are hoping another company is interested in the naming rights.
The owners had said that the name could have stayed but the corporation said they wanted to make it a clean slate.