The internationally recognized government in eastern Libya will try to stop any tanker operating for Glencore Plc from loading oil at the nation’s ports if the company does business with a rival political leadership in the west of the divided country, the head of the state-run National Oil Corp.’s eastern management said. The NOC in Benghazi in eastern Libya sent a letter to Glencore seeking to confirm whether the commodity trader and miner has reached an agreement for oil sales with the competing NOC arm based in the western city of Tripoli, said Nagi Elmagrabi, chairman of the eastern NOC. Glencore hasn’t responded, he said Monday in a phone interview. Mohammad Elharari, a spokesman for the NOC’s western administration in Tripoli, confirmed by phone that it has made a deal with Glencore to help market oil. He declined to give further details. Glencore declined to comment.