bhp...again ?, page-11

Regan, not my reasons. But there is a longstanding business relationship between successive WA governments (of both political persuasions) and Woodside. Here's the media report of a particular statement in 2011:

Mr Barnett said he had been informed of BHP's plans for Woodside in an "informal chat" with the Anglo-Australian resources giant.

Speaking at an oil and gas conference in Perth, he signalled he would fight to protect Woodside's independence if BHP sought to acquire more than Shell's 24 per cent stake.

"Develop a new field, find gas, find oil, find new customers, but I urge you -- hands off Woodside," the Premier said.

(http://www.heraldsun.com.au/businessold/hands-off-wa-premier-colin-barnett-warns-bhp-on-woodside-petroleum/story-e6frfh4f-1226037462492 accessed 13-Jan-2012 19:04 AEDT)

But it's also worth checking out WA Parliament question time records:

... if we look at the history of the development of the gas industry in this state, there has been the most significant transformation of the Western Australian economy for probably 40 or 50 years since the initial development of Pilbara iron ore. The emergence of the petroleum industry as the second-biggest sector has not only transformed the industry, but also it is transforming Perth.
That has happened over the past 20 years or so. It started in 1984, with the development of the domestic gas plant and the construction of the natural gas pipeline to Perth that allowed the development of the alumina industry and other things to happen. Woodside was the leader of that project. Then we had the export phase in 1989; Woodside was one of the six joint venture partners in the North West Shelf project, and it was the operator and the contact between the project and both state and federal governments. It was, in every sense, the Australian face of the project. I think that has been important not only for the development of Woodside’s projects, but also, indeed, for the whole of the Carnarvon and, prospectively, the Browse Basin areas. I think Australian people feel more comfortable with the high level of foreign investment in that sector because Woodside is a major player—although it is a mid-level, mid-tier petroleum company by world standards—that has its headquarters in Western Australia and is an Australian-owned company. I think it is important to preserve that. The point I made to the industry was simply as I expressed—hands off Woodside.

(http://www.parliament.wa.gov.au/parliament/pquest.nsf/3f9c0f35f2b504544825718e001105c9/b49691cce3cb7de348257873002d59c4?OpenDocument accessed 13-Jan-2012 19:09 AEDT)

Now WA Premiers are not Cwth FIRB, but that's a heck of a headwind for a potential suitor to work against. Probably easier to continue with the JV-dominated status quo.