Sino Gas & Energy's suitor Lone Star made three earlier takeover proposals at lower prices before securing the backing of the target's board for its $530 million deal, giving grounds for what chief executive Glenn Corrie says is growing support for the offer from investors.

The US private equity giant first made a takeover proposal to Sino, Australia's only indigenous gas producer in China, in December, at 17¢ a share. That followed an initial meeting with the board in September last year, according to sources.