CALGARY, Alberta (Reuters) – ConocoPhillips (COP.N: Quote, Profile, Research, Stock Buzz) is seeking a buyer for 50 percent of a large portion of its Canadian oil sands holdings, assets that could eventually produce more than half a million barrels a day, the firm handling the offering said on Monday.

Scotia Waterous said ConocoPhillips, now in the process of splitting its producing and refining assets into separate companies, is offering a share in six Alberta properties that currently produce 12,000 barrels a day from an estimated 30 billion barrels of bitumen in place.

The Houston-based oil major is putting the stake on the block as interest in the oil sands among investors, especially from China and other Asian countries, booms.

In the latest deal two weeks ago, PetroChina (601857.SS: Quote, Profile, Research, Stock Buzz) agreed to buy out its partner in a newly approved tar sands development for C$680 million ($674 million). In total, Chinese enterprises have spent nearly $5.5 billion on Canadian energy assets in the past six months.

ConocoPhillips already has a major oil sands and oil refining joint venture with Calgary-based Cenovus Energy Inc (CVE.TO: Quote, Profile, Research, Stock Buzz) under which the pair are developing the Foster Creek and Christina Lake projects.

Now, the company is offering a half interest in its Surmont, Thornbury, Clyden, Saleski, Crow Lake, McMillan Lake assets, Scotia Waterous said. The land totals 715,000 acres.

($1=$1.02 Canadian)

KITIMAAT VILLAGE, British Columbia (Reuters) -

Aboriginal chiefs opposed to a C$5.5 billion ($5.4 billion) oil sands pipeline backed Canada’s government vowed on Tuesday to stop the project, warning that it could devastate fishing and traditional life on the rugged Pacific Coast.

As hearings into Enbridge Inc’s proposed Northern Gateway pipeline opened with drumming and native singing, seven leaders of the Haisla First Nation told the regulatory panel their greatest fear was the potential impact of oil spills on their community of 1,500.

At stake, they said, are the salmon, halibut and crab fishing and fur trapping that have sustained the Haisla for generations.

“It worries me to think that all of these will be lost and destroyed when there is a spill – mark my words – when there is a spill. Experience shows it will happen,” Hereditary Chief Sam Robinson, 78, told the panel hearing Enbridge’s application.

The oil industry and Ottawa are pushing hard for the project, especially after Washington delayed the $7 billion Keystone XL pipeline to Texas, as they seek new markets for the Alberta oil sands, the world’s third-largest oil deposit.

The proceedings, expected to last two years, began at the community center in Kitimaat Village on the Pacific Coast’s Douglas Channel, the terminus of the proposed pipeline. Battle lines have already been drawn between supporters on one side and environmental groups and aboriginals in the province of British Columbia on the other.