Eugene Mitcham, 66, from Eaton Road, Kempston, was convicted on Tuesday, January 10 following a trial at Luton Crown Court.
During the trial the jury heard how Mitcham sexually abused two girls over a period of years from 1974 to 1980. The girls were aged just eight and 11-years-old when the abuse started.
Det Con Samantha Shane said: “I’m really pleased that Mitcham will be made to pay the price for his sickening actions, despite the length of time that has passed since the offences took place.
“It is never too late to report abuse and I hope that this case shows to others that if you come forward, you will be listened to, you will be believed, and justice can be done.”
Mitcham will be sentenced on January 27. He was cleared of six other child sex offences.