PORTLAND, Maine — A Topsham man was sentenced Friday in U.S. District court to four years and nine months in federal prison on gun charges.

Dennis Grenier, 33, also was sentenced to three years of supervised release by U.S. District Judge Nancy Torresen.

He was indicted in March by a federal grand jury in Portland. Grenier pleaded guilty May 30 to being a felon in possession of a firearm and possessing a firearm with an obliterated serial number.

By pleading guilty, Grenier admitted that he sold a gun with an obliterated serial number in March 2011 to an undercover ATF agent. Grenier was forbidden to possess guns because of a 2000 conviction in Kennebec County Superior Court for criminal threatening with a dangerous weapon.

He faced up to 10 years in prison on the possession charge and up to five years in prison on the obliterated serial charge. Both charges carried a potential fine of up to $250,000. Under the prevailing federal sentencing guidelines, Grenier faced between four years and nine months and five years and 11 months in prison.