With a state-owned Chinese company’s $15.1 billion bid to purchase a Canadian oil and natural gas producer with U.S. assets drawing opposition in Washington, the Canadian energy company has enlisted Covington & Burling for help.

The U.S. subsidiary of Calgary, Alberta-based Nexen Inc. has acquired a team of three Covington lobbyists to advocate for it on its proposed sale to Chinese energy company CNOOC Ltd., according to lobbying registration paperwork the law firm filed with Congress last week. Covington senior counsel Martin Gold, who is a co-leader of the firm’s government affairs practice group, as well as partner Gerard Waldron and special counsel Muftiah McCartin, are handling the account.