The army already has more than 100 M113 units. The latest batch would be fitted with 76mm turrets from decommissioned tracked Scorpion combat and reconnaissance vehicles, the Philippine Star reported.
"[The vehicles] will be fitted with modern fire control and thermal imaging equipment," army spokesman Capt. Anthony Bacus said. "Once it is completed, the 76mm cannon-armed M113s will be quite lethal."
The FV101 Scorpion was one of a family of armored combat and reconnaissance tracked personnel carriers manufactured by the British car and military vehicle company Alvis.
Several thousand were produced starting in 1973, with the last vehicles withdrawn from British service in 1994.
The low-velocity 76mm L23A1 gun made by British Aerospace Defense's Royal Ordnance division can fire high-explosive squash-head ammunition as well as smoke and canister rounds.
BAE Systems bought Alvis Vickers in 2004 and United Defense Industries in 2005. That same year BAE merged them with its own Land Systems division to create BAE Systems Land and Armaments, with headquarters in Arlington, Va..
Many of the Philippine army's M113 vehicles have come from the U.S. Army which is phasing them out in favor of the M2 and M3 Bradley, also made by BAE Systems Land and Armaments through its acquisition of UDI.
The Philippine purchase is part of the Department of National Defense's ongoing $1.9 billion modernization of the Philippine armed forces through 2018.
Military website BreakingDefense reported in March last year the U.S.Army was going to replace its M113 vehicles after more than 50 years in service.
Breaking Defense reported the contract worth up to $1.5 billion for more than 300 units was expected to be finalized by the middle of this year with final deliveries by 2020.
Also last year, the Philippine army bought new wheeled M1114 armored Humvees -- high mobility multipurpose wheeled vehicle -- as well as M939 and M35 trucks from the United States, the Philippine Star reported.
Humvees are made by AM General, which builds the frames, and bodywork and armor plating specialist O'Gara-Hess Eisenhardt.
The new fighting vehicles provided fire support during the Zamboanga siege in September.
The army was called out to Zamboanga City in the southern Philippines to fight units of a faction of the insurgent Moro National Liberation Front that had captured areas of the city.