From late August through mid-November 2011, Rio Tinto and Cameco engaged in competitive bidding for Hathor Exploration, a Canadian uranium exploration company with uranium properties in the Athabasca Basin of northern Saskatchewan. Rio Tinto prevailed with an all-cash offer made on November 17 to acquire all outstanding Hathor common shares for C$4.70/share, valuing Hathor at about C$654 million. On November 28, Cameco announced it would not increase or extend its November 11 offer of C$4.50/Hathor share. Rio Tinto followed the Cameco announcement with an announcement of its own, urging Hathor shareholders to promptly tender their shares to its C$4.70/share offer.

Earlier, Rio Tinto had offered C$4.15/share on October 19, and Cameco had offered C$3.75/share on August 26. On September 14, Hathor’s board unanimously recommended that its shareholders reject the initial Cameco offer because it had been made prior to Hathor’s planned release of a preliminary economic assessment for its Roughrider uranium deposit. On November 22, Rio Tinto reported its C$4.70/share offer had received Canadian Competition Bureau clearance.

On September 13, Hathor reported indicated mineral resources in the Roughrider deposit’s West Zone of 394,200 mt, grading 1.98% U3O8 and containing 17.2 million lb of U3O8, as well as inferred resources in the West Zone totaling 43,600 mt, grading 11.03% U3O8 and containing 10.6 million lb of U3O8, and inferred resources in the East Zone totaling 118,000 mt, grading 11.58% U3O8 and containing 30.1 million lb of U3O8.