The three 44.5-meter-long (146-foot) craft, which are designed to carry heavy supplies, will be acquired and refurbished at a cost of around P726 million ($16.5 million), said Department of National Defense public affairs chief Arsenio Andolong.
"By market standards, these are almost giveaway prices," he told AFP.
"These vessels will be used for humanitarian assistance and disaster relief," Andolong said.
The Australian embassy confirmed that the Philippines had expressed its intention to purchase the three vessels.
Australian Defense Minister Kevin Andrews previously announced that two of the same ships would be donated to the Philippines to help with humanitarian assistance and relief work, and would arrive in the Southeast Asian archipelago in May.
Australia saw the need for such vessels after a shortage during relief operations following Super Typhoon Yolanda, Andolong said.
Yolanda, the strongest storm ever recorded on land, decimated whole towns and villages when it struck in November 2013.
The Australian military were dispatched to help victims of the storm, which left more than 7,350 people dead or missing.
"They know we are typhoon prone and they saw the effects of [Yolanda] on us," Andolong said.
The poorly-equipped Philippine military is one of the weakest in the region and the government is looking to foreign allies to help bolster its resources.
The Australian Navy's three remaining Landing Craft Heavy auxiliary vessels put on a display to the Cairns community.