The complainant had said she was indecently assaulted by Parkin on a couch and that on another occasion, when she was only 11, Parkin forced her to touch his groin.
"Imprisonment is very much on the cards," Judge Robert Ronayne told Parkin, who is now on bail awaiting sentencing in May.
The trial
Parkin faced five charges of indecently assaulting young girls in Whangarei, Auckland and Coromandel between 1975 and 1983.
Crown prosecutor Fiona Culliney told the trial Parkin abused the young girls on separate occasions.
The trio did not mention the alleged abuse to anyone for years, Culliney said.
Two of the girls were encouraged to lay a complaint with police by a person close to Parkin and police began investigating in 2016.
A third complainant came forward after seeing media reports about the allegations.
Eleven of the 12 jurors found him guilty of two charges related to the second of three complainants.
The second complainant said she was indecently assaulted by Parkin in an Auckland home and said that on another occasion, when she was only 11, Parkin forced her to touch his erection.
The jury decided unanimously that he was not guilty on the three other charges.
