Australia's BHP Billiton (NYSE: BHP), the world's largest mining company, may soon extend its string of bad luck in chasing acquisitions. Earlier this month, it looked as if the company just might pull off its purchase of PotashCorp (NYSE: POT), but that probability might be shrinking.

Indeed, before this week has run its course, the government of Saskatchewan might signal to Canadian federal officials its opposition to the combination. While the province doesn't have complete control over whether BHP's nearly $40 billion offer for PotashCorp is accepted, a negative recommendation from the provincial government almost certainly would squelch the deal.

Critics in Saskatchewan believe the province could lose $2.9 billion in revenues during the next 10 years if BHP deducts the cost of developing another potash mine from earnings generated by PotashCorp. Thus far, and despite extensive discussions between the company and provincial officials, BHP is resisting the $1 billion up-front tax payment that Saskatchewan officials demand.

All this comes within about two weeks from the receipt of a report commissioned by the provincial government and prepared by the Conference Board of Canada. That report, while not wholeheartedly endorsing the BHP offer, indicated that the Aussie company's purchase would be less threatening to Saskatchewan than possibly competing Chinese offers.

Within the past week, BHP and its fellow mining giant Rio Tinto (NYSE: RTP) have also scuttled plans for a joint venture that would have combined their Western Australia iron ore operations. Indications that the European Union wouldn't approve the combination effectively blocked the venture, marking another political setback for BHP.

But even if Saskatchewan thwarts its PotashCorp purchase, I doubt that setback will knock BHP off the acquisition trail. Indeed, even though its original 2008 offer fell apart, a renewed effort to merge with Rio hardly seems unreasonable. Furthermore, I'd even speculate that companies such as Freeport-McMoRan Copper & Gold (NYSE: FCX) or aluminum manufacturer Alcoa (NYSE: AA) could also put a gleam in BHP management's eyes.

And speaking of eyes, I'd urge Foolish investors to keep their peepers fixed on the opportunities offered by this massive and active mining, minerals, and energy company.