MANILA - Philippine conglomerate San Miguel Corp. is looking to buy oil and natural gas fields overseas as it seeks to expand its energy portfolio, its president said on Wednesday. 

The company has a full force of staff studying possible acquisitions in that area, San Miguel President Ramon Ang told reporters. 

"We will only buy into oilfields that have proven output," he said. 

San Miguel, with a market value of $7 billion, has expanded over the last four years into sectors such as power, telecommunications, mining, infrastructure and recently airlines.