Shares in Sirius Exploration, the only London-listed potash company, have kept on rising after an initial boost from the hostile takeover bid for Potash, the world's largest fertilizer producer.

BHP Billiton's $39 billion bid for Potash lifted the shares of companies involved in the crop nutrient on takeover speculation, but while others, such as Germanys' K+S and Norway's Yara, have slipped back or just clung on to their gains, Sirius's recent good fortunes have kept a fire under its stock.

"BHP was the main trigger for Sirius to start being looked at in more detail," said Tom Hayes, analyst at Edison Investment Research. "The potash outlook is good; demand will increase in parallel with population growth, especially with regard to China and India."

Sirius's shares have tripled since Aug. 17, but are still only back to their highest level since December after the stock dropped last year on aggressive selling following the acquisition of four potash and salt projects in Australia and the United States.

A new chairman in April and positive project updates in August have caught the eye of investors that might initially have been attracted by renewed interest in the crop nutrient. "The timing has been good," said Hayes.

Chris Catlow took over as chairman on April 6 and instigated a strategic review. He was a senior executive of Fortescue Metals, a company widely respected in the mining world for making the transition from a junior in 2003 to become Australia's third-largest iron ore producer.

Last month, Sirius said Sino-Agri Mining, part of China's No. 2 fertiliser distributor, plans to develop Sirius's property overlying the Adavale Basin in Queensland, Australia. It also received an exploration permit for Dakota Salts, the first potash permit issued by North Dakota in over 30 years. Dakota Salts is focused on the large salt deposits along the North Dakota-Canadian border overlying the Williston Basin, where Sirius plans to start its first drilling campaign in 2010.