Barilaro's appointment as the NSW Senior Trade and Investment Commissioner to the US, a position he created when he was trade minister, has come under immense scrutiny from ministers.
The former deputy premier's appointment to the sought-after role comes just six months after he resigned from politics.
Perrottet today conceded Barilaro told him personally he wanted the role at a social function.
"In a social setting he may have said that he was applying for a position, for which there was an independent process," Perrottet said.
Perrottet claimed he gave Barilaro no feedback on whether he thought the appointment to the role was appropriate.
He is also adamant that Barilaro was not promised the role when he was still in parliament.
"John Barilaro is a former trade minister who went through an independent process," Perrottet said.
"There was no talk about a future job in terms of why he was resigning."
Perrottet has now ordered an independent review of the appointment process to provide "public confidence" in the government's decision-making.
Meanwhile, a parliamentary inquiry examining the hiring process begins tomorrow.