OTTAWA — Apparently looking to exploit the collapse of oil prices, Suncor, the largest integrated energy company in Canada, announced a hostile takeover bid for Canadian Oil Sands on Monday that it valued at 6.6 billion Canadian dollars.

If successful, the transaction will give Suncor control of Syncrude, Canada’s largest oil sands operation, in addition to its own oil sands holdings. Canadian Oil Sands’ only asset is a 36.7 percent stake in Syncrude; Suncor currently owns about 12 percent of Syncrude.

Canada’s oil sands industry has been hit more severely by falling prices than conventional oil producers because of substantial costs related to creating crude oil from its deposits of tarlike bitumen.

During a conference call, Steve Williams, Suncor’s president and chief executive, said Canadian Oil Sands rebuffed a proposal by his company for a friendly takeover earlier this year. On Monday, he emphasized that the transaction offered a 35 percent premium over Canadian Oil Sands’ average weighted price over the last 30 days.