A liberal group launched an online petition Friday demanding that potential secretary of State nominee Susan Rice divest herself of “every dollar of stock” in the Canadian company seeking approval for the controversial Keystone XL oil pipeline to the Gulf Coast.

The U.S. ambassador to the United Nations owns between $300,000 and $600,000 in TransCanada Corp. stock, according to her financial disclosure forms. The pipeline needs approval from the State Department before it can go forward.

The revelation has opened Rice up to criticism from environmentalists at a time when several Senate Republicans have vowed to oppose her because of her early statements about the Sept. 11 attack on the U.S. Consulate in Benghazi.