First Gen announced in a stock exchange filing on Monday the closing of the transaction.
Razon-led Prime Infra said in a separate press release that it has reached the financial close of its transaction worth 50 billion pesos ($847.4 million) to acquire and operate the gas assets of First Gen.
Last month, First Gen revealed that the Philippine Competition Commission cleared the acquisition.
Earlier this year, First Gen entered into the deal with Prime Infrastructure.
Following completion, Prime Infra now owns 60 percent of the issued and outstanding capital stock of five power plants, all located in Batangas City.
First Gen has a portfolio of four gas-fired power plants with a combined capacity of 2,017 MW that have been supplied for many years with gas from the Malampaya offshore gas field.
These include the 1000 megawatt (MW) Santa Rita power plant, the 500 MW San Lorenzo power plant, the 450 MW San Gabriel power plant, the 97 MW Avion power plant, and the proposed 1200 MW Santa Maria power plant.
The transaction also includes the interim offshore LNG terminal.
Prime Infra will own 60 percent of the Batangas gas plants, with First Gen owning 40 percent.
Meanwhile, Prime Infra will hold 60 percent in the LNG import terminal, while First Gen and Japan’s Tokyo Gas will each hold 20 percent.