Rio Tinto (NYSE:RIO)(LON:RIO), the world's third-biggest mining company, Wednesday agreed to pay $578 million to acquire uranium explorer Hathor Exploration (TSE:HAT), trumping a $520 million hostile bid by Cameco (TSE:CCO).

"The offer does not reflect the strong economic parameters for Roughrider, it does not take into account the mineralization and mineral resource potential at the Far East Zone, it does not capture the scarcity value of quality projects like Roughrider in comparison to other available undeveloped uranium deposits around the world," Hathor said in a statement on Tuesday.

Junior uranium company Hathor Exploration (TSE:HAT) Wednesday rejected a $520 million hostile bid from Cameco (NYSE:CCJ)(TSE:CCO), calling the offer predatory and too low.

Hathor Exploration (TSE:HAT) said a preliminary economic assessment of its flagship Roughrider uranium deposit in Saskatchewan showed it would potentially be one of the lowest cost uranium producers in the world.

Hathor’s resource base at Roughrider has tremendous potential to grow via delineation of Roughrider East. Indeed any  takeover premium will be influenced by the extraordinary richness of the grades...

Mountain Lake Resources (CVE:MOA) (OTC:MLKRF) Thursday said it will be acquired by Marathon Gold (TSE:MOZ) in a  $15.1 million deal that will see Marathon assume 100 per cent control of the two companies' Valentine Lake joint venture in Newfoundland.

A recent resource upgrade highlighted the world-class potential of Elemental Minerals’ Kola potash deposit, which is part of its Sintoukola property in the Republic of Congo. The company has deliberately remained below the radar, allowing the project to speak for itself. The latest results promise to lift the veil of anonymity.

EurOmax Resources' (CVE:EOX)(OTCQX:EOXFF) share consolidation is the first step in a process that will transform the junior explorer into a London-based exploration and development company.

Silver Bull Resources (TSE:SVB)(AMEX:SVBL) Tuesday said a new NI 43-101 report currently being completed will show a 39 per cent increase in the open pittable resources at the Shallow Silver Zone at its Sierra Mojada project in Mexico.

Geomega Resources (CVE:GMA) unveiled Thursday preliminary metallurgical results from its Montviel rare earths-niobium project near Level-sur-Quévillon, Québec, with recoveries as high as 97% total rare earth oxides (TREO).