Shareholders voted 99 per cent to approve the split of Calgary-based EnCana into two new companies Wednesday.

One, focused on natural gas exploration and production, will retain the EnCana name. The other, Cenovus, will become an integrated heavy oil producer.

Cenovus' oilsands extraction facility in northern Alberta. Cenovus will become one of Canada's largest heavy oil and oilsands producers. (Cenovus)

Not since 2001, when Canadian Pacific Enterprises spun off its five divisions, has a large Canadian company spun itself off into new companies.

The theory is that mixing two commodity operations in one company muddles the markets' perception of their values, whereas splitting them will improve their share prices as investors are attracted to each as a pure play on the price of either oil or gas.

EnCana originally announced the split in the spring of 2008 but put the plan on hold because of the global financial crisis. Then, its shares were trading in the $100 range. On Tuesday, they closed below $56 on the Toronto Stock Exchange.

EnCana will become the second-largest natural gas producer in North America, with stakes in shale basins in northeast British Columbia, Louisiana and Texas. Cenovus will become one of Canada's largest heavy oil and oilsands producers.