Infratil has improved its full year profit by almost $55 million to over $438 million.

It was boosted by big contributions from its Metlifecare and RetireAustralia investments.

The company's controlling stake in electricity generator Trustpower, its retirement village investments, NZ Bus, and Wellington International Airport units all delivered increased earnings.

It's 2017 earnings guidance is between $475 million and $515 million.

A final dividend of nine cents per share will be paid next month taking the annual dividend to 14.25 cents.