Enbridge Inc., Canada's No. 2 pipeline company, said on Monday it will spend $1.2 billion to twin its Athabasca regional pipeline, which serves oil sands projects in northern Alberta. Enbridge will build a new 450,000-barrel-per-day pipeline along the same right of way as its existing Athabasca line, which is currently being expanded to carry 570,000 barrels per day.