TCW is offering $1.51 per share for all the remaining stock in QGC, a 5% premium to AGL’s proposal and 11% higher than Tuesday’s closing price, it said.

QGC said its board would consider the offer and discuss the issue further at an extraordinary general meeting tomorrow, March 2.

This is not the first time TCW has made a grab for QGC, making initial exploratory contact in August before Santos launched its own, now failed, takeover bid.

Back then it was proposing a three-way marriage involving itself, at least two of the major shareholders and AGL Energy, which would also receive a long-term gas supply contract. But QGC rejected the $1.40 bid.

AGL then decided to ditch TCW and launch a separate proposal in which it would take a 27.5% stake and its own 20-year gas sales agreement.

Under the latest proposal, TCW has agreed to offer QGC shareholders payment in either cash, preference shares or a combination of both.

In a statement today, TCW group managing director Blair Thomas said the latest offer was “clearly superior” to AGL’s proposal.

“Our offer provides QGC’s shareholders with superior value and … the opportunity to participate for all their shares, unlike the AGL proposal, which only includes a 12.5% buyback option,” Thomas said.

Thomas said TCW had a “capital intensive” development plan for QGC’s Undulla Nose coal seam methane assets.

“In addition to the development of QGC’s assets, we will seek to address existing infrastructure bottlenecks that inhibit efficient development of eastern Australian gas markets.”

TCW’s offer is subject to certain conditions such as a minimum 50.1% shareholding and the termination of the partnership agreement between AGL and QGC.

Los Angeles-based TCW, which has about A$150 billion of assets under management, counts public pension plans, financial institutions, US foundations and foreign investors among its clients. The company is one of the world's largest investors in CSM, it said.

The company's energy and infrastructure unit has more than $7.4 billion invested in more than 190 energy projects and owns stakes in five major CSM operations, mostly in the US and Canada.