The 26-year-old "La Tapageuse" vessel is likely to be the first of several French ships that will be acquired by the Philippine coastguard as it contends with increasingly assertive Chinese forces.
The 54.8-metre (180-foot) patrol ship will cost six million Euros ($7.97 million) and is due to arrive in the country by April next year, a coastguard statement said.
The ship, which is armed with two cannon and two machine-guns, was inspected before acquisition and is good for 20 more years of service, the coastguard said.
"This French vessel is multi-functional and it would be a major contribution to our fleet, particularly in our search and rescue operations," coastguard chief Rear Admiral Rodolfo Isorena was quoted as saying in the statement.
The Philippines is also "finalising" with the French government the purchase of four brand-new 24-metre and one 82-metre multipurpose vessels, Isorena said.
These new ships would arrive in the first quarter of 2015, the statement added, without specifying their cost.
Isorena also recalled that the Philippine coastguard was already set to acquire 10 multi-role patrol boats under an aid programme with Japan.
The announcement came as a second-hand US Hamilton-class cutter acquired by the Philippine Navy sailed into the country's waters, where it will also help
in patrolling the South China Sea.
Tensions have risen in recent years over China's increasingly-forceful claims to almost all of the South China Sea, even up to the coast of its neighbours like the Philippines.
These tensions have worsened since Chinese government vessels seized the Scarborough Shoal, a South China Sea outcrop just 230 kilometres (140 miles)
east of the main Philippine island of Luzon, last year.
The Philippines has also complained about the presence of Chinese navy vessels near the Manila-controlled Second Thomas Shoal in the Spratly Islands.
The Philippines has one of the most poorly-equipped militaries in the region and has been trying to beef up its armed forces in the face of the maritime disputes