Suncor not ruling out sweetening offer for Canadian Oil Sands

[caption id="attachment_841756" align="aligncenter" width="600"] Syncrude’s $1.9 billion centrifuge plant, currently under construction. (Image courtesy of Syncrude, via Flickr)[/caption] Suncor Energy (TSX, NYSE:SU), Canada’s largest oil and gas company, has not ruled out raising its offer to acquire Canadian Oil Sands (TSX:COS),...