TransCanada Corp. is dramatically expanding its effort to win public support for its proposed $12-billion Energy East project, including an effort to target opposition groups that are gearing up to fight the project in central and eastern Canada.

Documents obtained by Greenpeace and released late Monday show the embattled pipeline company has hired the world’s largest public relations firm, Edelman, which has a reputation for aggressive tactics in the United States and proposed a similar approach in Canada in a strategic plan completed in August.