The Philippines' most diversified conglomerate San Miguel Corp is in talks to sell its unlisted banking unit soon and is eyeing an overseas oil and gas acquisition, as it seeks to build a stronger portfolio after walking away from a two-year airline investment, its president said on Wednesday. San Miguel, which embarked on an aggressive expansion drive starting in 2008 that saw it add power, mining, telecoms, oil refining and infrastructure to its stable of food and beverage businesses, is actively pursuing an offshore oil and gas deal, but is not in a hurry to seal an acquisition, Ramon Ang said.