The Chinese government has backed Sinochem, the state-owned chemicals giant, to pursue a counterbid that could trump BHP Billiton’s $39bn hostile offer for PotashCorp in a sign of Beijing’s interest in securing global resources.

Sinochem, Aluminum Corp of China, and other Chinese state resource companies initially shunned bankers pitching counterbid ideas for the Canadian fertiliser company, a person familiar with the matter told the Financial Times.

But the government has encouraged Sinochem to “take an interest” in PotashCorp, according to the person. Only after a signal from the government did the state-owned company begin to entertain bankers’ proposals.

The likelihood of a counterbid remains unclear. Mining analysts say that the size of BHP’s $39bn opening offer is the biggest impediment, because few other private companies in the sector can match the financial strength of the world’s biggest mining group.

But Chinese government-owned companies have access to deep pool of funds, either through soft loans from state banks or via the involvement of China Investment Corp, the country’s sovereign wealth fund. The Sinochem Group controls almost all potash imports into China through Sinofert, its listed subsidiary. PotashCorp owns a 22 per cent stake in Sinofert.

China is the world’s largest importer of potash, a mineral that is used to enhance crop yields. Beijing’s new interest in the bid is the strongest sign yet of its concern that a successful BHP acquisition could have long-term implications for its food security.

Beijing has made grain self-sufficiency a domestic priority to ensure affordable food prices and dependable supplies to 1.3bn citizens. More than two weeks after BHP’s $130 per share offer, no counterbid has emerged. But speculation now centres on a Chinese state-backed entity partnering with a Canadian company.

Any Chinese-led counterbid for PotashCorp would carry risks of a political backlash in Canada and especially Saskatchewan, the potash-rich province whose government has sway over the bid’s outcome. Sinochem has never done a deal of this size overseas. It failed to complete a deal with Nufarm, an Australian fertilisers group, in 2009 after six months of talks.