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 the offer 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 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.