(Adds CEO quote, details on transactions, power plant)
SANTIAGO, March 28 (Reuters) - Chilean energy company AES Gener SA said on Friday it was bringing in investment fund Global Infrastructure Partners (GIP) as a minority partner to run the Guacolda thermoelectric plant in the north of the Andean country.
AES Gener, a local unit of U.S. power group AES Corp , already owns a 50 percent stake in the roughly 608 megawatt coal-fired complex located in Huasco.
The plant's other two shareholders - industrial firm Empresas Copec and Inversiones Ultraterra - have been seeking to sell their respective 25 percent stakes in Guacolda.
AES Gener, Chile's second-largest energy generator, said on Friday it had accepted a preferential offer to buy up that 50 percent stake for $728 million.
Once that purchase is concluded, the company will sell 50 percent less one share to GIP, a fund founded by Credit Suisse and General Electric that owns London's Gatwick Airport, among other infrastructure projects.
That transaction would be made "at terms substantially similar to those of the acquisition previously made," AES Gener said in a statement.
AES Gener was "very pleased to include GIP as a partner since it has broad expertise in the energy and infrastructure sectors," said Chief Executive Officer Luis Felipe Ceron.
The Santiago-based company, which supplies power to major miners, including state company Codelco and global company BHP Billiton, had told Reuters in January it could increase its stake in Guacolda.
The power plant contributed around 9 percent of generation of Chile's central SIC energy grid in 2012, according to a document on its website.
AES Gener said it was financing the deal with a $700 million credit agreement with Deutsche Bank AG, London Branch, and Sumitomo Mitsui Banking Corporation Deutsche.
(Reporting by Alexandra Ulmer; Editing by David Gregorio, Bernard Orr)