The Federal Trade Commission in the United States has given its approval to the merger of two of the world's largest oil companies, British Petroleum and Amoco.

The Commission chairman said he was satisfied that the operations of Amoco and BP rarely overlapped in a way that threatened competition.The fifty-billion dollar merger, which was first announced in August, is one of the largest in business history.

It follows the announcement of a similar merger between Exxon and Mobil, creating the world's largest company.

Correspondents say both mergers are driven, in part, by the need to reduce costs at a time of low oil prices.

The companies hope to save millions of dollars by cutting costs and shedding staff.