A former Massachusetts man who had a three-year sexual relationship with a female relative starting when she was 15 has pleaded guilty to child rape and incest charges.

Louis Walters of Durham, N.H., was sentenced Thursday in Salem Superior Court to eight to nine years in state prison.

He faces similar charges in Strafford County Superior Court in New Hampshire next week, where he’s expected to receive a 10- to 20-year term on similar charges involving the same girl. Authorities say she moved with him when he moved to New Hampshire.

Prosecutors say the relationship started when the now 38-year-old Walters moved in with the girl’s parents in 2005.

His defense lawyer urged a judge to accept a deal worked out with prosecutors in Massachusetts and New Hampshire that allows Walters to serve the sentences concurrently.