Environment Minister Josh Frydenberg has defended the government's decision to give almost half a billion dollars to a private sector charity, saying the lump sum grant, delivered without a tender process, was "not unusual".

"When the Labor Party provided billions of dollars to the coal generators, they put it out in one hit and didn't run a tender process either," Mr Frydenberg said on ABC Insiders on Sunday.

"The [Great Barrier Reef] Foundation was chosen because it is the best organisation to leverage off the private sector."

Environment Minister Josh Frydenberg. Credit:Alex Ellinghausen

"My department has made it very clear that the guidelines were complied with, that it represented value for money and it was the best way to deal with the urgent need of putting money into the foundation," he said.