The Philippine government is acquiring two anti-submarine helicopters, worth about 5 billion pesos ($121 million), in line with its military modernization program.

Defense Undersecretary Fernando Manalo said Monday they are considering buying four different types of anti-submarine helicopters. He would not elaborate but sources said the four includes AgustaWestland AW-109, a twin-engine, eight-seat multipurpose chopper.

"We are just waiting for the issuance of the acquisition decision memorandum (from Defense Secretary Voltaire Gazmin). We will deploy them (helicopters) with the frigates that we are also trying to acquire," Manalo said.

He is referring to the two Maestrale-class frigates that the department is eyeing to purchase from Italy.

Manalo said the fund to be used in the acquisition of the two helicopters will come from the 75 billion pesos ($1.82 billion ) budget for the five-year modernization program.

The budget is incorporated in a bill that seeks to extend the military's modernization law for another 15 years. The old modernization law, passed in 1995, lapsed last December.

Manalo said the department is working on the planned acquisition, pending the extension of the modernization law. He said such acquisitions would be implemented by way of contract if the bill was signed into law.