Rio Tinto has won a 70.21% stake in uranium exploration company Hathor Exploration, based in Vancouver, Canada, for a total sum of $A627m (US$641.6m).

The company has extended its offer to acquire Hathor Exploration’s 94,950,089 common shares for $4.64 in cash within ten days.

All of the conditions of the offer, made through an indirect wholly owned Canadian subsidiary, have been satisfied.

Rio Tinto has extensive operations in Canada, which include mining and manufacturing interests in alumina, aluminium, iron ore, diamonds and titanium dioxide.