Nicholas Parkinson of Leigh in Wigan, was sentenced at Bolton Crown Court, after being found guilty of eight counts of indecent assault and two counts of indecency with a child.
The court heard how Parkinson had preyed on the youngsters, who were all aged under 10 at the time.
Detective Constable Cheryl Williams of GMP’s Major Incident Team said: “Nicholas Parkinson is a predator of the worst kind and this sentence is the culmination of a lengthy and complex investigation.
“I would like to commend the strength of the victims, who have shown significant bravery in supporting this prolonged prosecution.
Although this sentence in no way makes up for the horrors that they sustained when young children, I hope that they can take some comfort and satisfaction from the fact that Parkinson is now behind bars for many years and no longer a threat to children.
“We would encourage anyone who has been a victim of sexual assault, or knows someone who has, to get in touch with GMP. We will listen to you and we will investigate.”