Australian Pipeline Trust has vowed to use its growing size to take on bigger projects after outbidding several larger companies to buy gas distributor Allgas from the Queensland government-owned Energex for $521 million.

Australian Pipeline chief executive Mick McCormack denied he had overpaid for Allgas, and said his company might even offer to relieve AGL of its unwanted lead role in developing a $4 billion pipeline to pump gas from Papua New Guinea to Australia.