* Canada's native chiefs reviewing treaty to block oil industry expansion

Mike De Souza

CALGARY (Reuters) - Native chiefs in the Western Canadian province of British Columbia voted on Wednesday to join some of their eastern counterparts opposed to a major pipeline project, in a move some leaders described as a step toward a national alliance aimed at blocking expansion of Alberta's oil sands industry.

The chiefs from British Columbia agreed to join opposition to the Energy East project - proposed by TransCanada Corp at the meeting, also attended by chiefs from the Canadian provinces of Ontario, Manitoba and Quebec. If approved, the Energy East pipeline would carry up to 1.1 million barrels of crude oil per day from Alberta's oil sands to the Atlantic coast, along a 4,200 km (2,850-mile) route.

Canada's oil sands in northern Alberta are home to the world's third-largest crude reserves but they also represent the country's fastest growing source of greenhouse gas emissions due to their energy intensive production methods. While the industry has said it needs to expand pipelines to give it access to new markets and promote responsible expansion, environmental and aboriginal groups and some municipalities across the country have opposed new projects, due to the risk of spills and the climate change impacts.

The native leaders also released a draft national treaty at the meeting, to be circulated among First Nations across the country, that would call for them to prohibit, challenge and resist use -whether by pipeline, rail or tankers - of their territories for expansion of oil sands production.