By DAVID FICKLING

Australia's New Hope said it wants to be taken over. It may have also signaled the top of Australia's coal market.

Last year New Hope made an unsuccessful tilt at Macarthur Coal before launching a long, sometimes hostile, but ultimately successful takeover of Northern Energy. On Wednesday, though, the company said it would seek suitors.

Though Australia is the world's biggest coal exporter by volume, locally listed companies actually mining the black stuff are becoming thin on the ground. Including deals yet to be finalized, Australia's inbound coal takeovers have been worth around 12 billion Australian dollars (US$11.7 billion) over the past year, or A$16.5 billion if you count takeovers of locally listed miners with overseas projects. That's about a quarter of all inbound mining deals in Australia over the past decade.

Most of Australia's coal is now owned by global giants such as BHP Billiton, Xstrata and Rio Tinto, or by emerging-markets companies such as India's GVK Power & Infrastructure and Adani Enterprises, which have snapped up most of the Galilee Basin, an undeveloped but potentially rich coal province in the country's northwest.

If current foreign bids for Coal & Allied Industries and Macarthur Coal are successful and New Hope succeeds too, only five independent pure coal producers will be left on the Australian Securities Exchange. Last year, that group produced just 10 million tons of coal—around 3% of the country's total. Of the remaining Australian coal miners, Gloucester Coal and Gujarat NRE Coking Coal are essentially part-owned subsidiaries of overseas groups, and Whitehaven Coal and Aquila Resources already seem keen to sell up. The entire output last year by Cockatoo Coal would barely fill a single shipment. With such a thin seam left this M&A boom, and the windfall it has brought to Australian investors, won't last much longer.

Patersons Securities says that valuations have declined with this thinning out of deal targets. Falling coal prices and concerns about the global economy also weigh. In the last six months, acquirers have paid around A$2.1 for each metric ton of coal in the ground, a 30% drop compared with last year.

On that basis, New Hope is worth about A$5 billion—including A$1.7 billion in net cash and deposits on its balance sheet. The implication of its switch from hunter to willing prey, though, suggests prices for Australian coal miners might already have peaked.

Write to David Fickling at david.fickling@dowjones.com

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