Richard Hunt, 31, of Virginia Drive, denied the offences but a jury took less than two hours to convict him following a trial.
Judge Simon Hirst, passing sentence, told Hunt: “You were on bail for count one at the time you committed count two.
“Plainly these offences are so serious that only a custodial sentence can be imposed.”
Hunt denied two charges of sexual assault of a child under the age of 13. The charges related to separate incidents on February 5 and August 30 last year.
He was placed on the sex offenders’ register for life, and given an indefinite sexual harm prevention order.
Tony Stanford, prosecuting, said that Hunt sexually assaulted the seven-year-old when he indecently touched her.
Then, while on bail, he carried out a further serious sexual assault on the four year old.
The court was told that Hunt had twice previously been jailed for offences of robbery but had no previous convictions for any offence of a sexual nature.
Edna Leonard, representing Hunt, admitted that her client had behaved in ‘an appalling way’ and told the court: “There is little I can say in the way of mitigation.”
She said that Hunt had been disowned by members of his own family after being charged with the offences and remanded in custody.
“His father, his siblings, none of them have had anything to do with him. Since he has been in prison he has had no contact whatsoever with any of them.”