Several Canadian oil-sands companies emerged as financial backers of Enbridge Inc.'s (ENB, ENB.T) controversial plan to build an oil pipeline to Canada's west coast in regulatory filings Wednesday.

France's Total SA (TOT, FP.FR), Suncor Energy Inc. (SU, SU.T), Nexen Inc. (NXY, NXY.T) and Cenovus Energy Inc. (CVE, CVE.T) all said in a filing with Canada's National Energy Board that they plan to ship oil on the Northern Gateway oil pipeline, which would transport up to 525,000 barrels of oil a day from Alberta to a port in Kitimat, British Columbia, and then on to markets in Asia.

The four companies are all oil-sands producers that are planning major expansions of their operations, and looking for more pipeline capacity to export production--especially to Asia, where the companies can fetch higher prices for their oil.

However, Enbridge's Northern Gateway project faces substantial resistance from native and environmental groups in Canada who said they oppose the pipeline due to the potential for spills on land and water, and due to the environmental effect of oil-sands development in Alberta.

The four companies named are also funding participants for the pipeline--meaning they are among several Canadian and international oil producers that have contributed a total of $100 million in preliminary funding for the project, which has been estimated to cost $5.5 billion to construct by 2017.

Other companies yet undisclosed may also be providing financial backing for Northern Gateway--the four were disclosed as a group because they used the same law firm to prepare the filing.

State-owned China Petroleum & Chemical Corp. (SNP, 600028.SH), or Sinopec, has been previously disclosed by Enbridge as one of the funding participants for the pipeline.