The agreement, signed in February, covers major engine services and spare parts for the three power plants - the diesel power station, interim power station and oil cubes - located at the mine.
In total, these power plants have 22 Wartsila engines with a combined output of 172 megawatts.
Wartsila service unit director Australasia John Sydney welcomed the agreement and said the companies were still negotiating rates for labour and parts for major services on the engines.
"We are very happy to deepen our cooperation with Newcrest Mining in the Lihir gold mine," he said.
"By drawing up the annual plans together and streamlining processes, we can ensure the timely completion of each major engine service, thereby increasing engine availability, improving operational efficiency and reducing costs."
The Lihir gold mine is about 900km northeast of Port Moresby and is thought to be built on one of the world' largest known gold deposits.
For the year ended June 2014, 721,264 ounces of gold were produced, adding to the nine million ounces produced at the mine, as at 2013, since mining began in 1997.
Newcrest expects production to ramp up to one million ounces per annum following major expansion works, including the installation of a new crushing facility and upgrades to the ore processing plant.
It is estimated that mining activities will continue until 2031 with ore processing operations projected to finish in 2044.