MCI and British Telecom tentatively agreed to build a new fiber-optic cable across the Atlantic. Capable of carrying at least 300,000 simultaneous phone calls, the cable would cost about $400 million. The two firms will seek other partners for the project.

Gas prices at the pump fell over the last two weeks for the first time since the Persian Gulf crisis, according to the Lundberg Survey. The national average price for all grades of gasoline fell 0.18 cent to $1.4691 per gallon.

Citicorp's senior debt rating was lowered by Standard & Poor's to A-plus from AA-minus, the second downgrade the No. 1 U.S. bank holding company has taken from S&P in seven months.

The Willard Hotel breached a contract and must pay Marquis Limousine Co. $100,000, D.C. Superior Court Judge Herbert B. Dixon Jr. has ruled. Other aspects of the case were settled out of court and the terms were not disclosed.

A South Korean farm lobbyist stabbed himself in the abdomen at the Geneva headquarters of the General Agreement on Tariffs and Trade, apparently to protest attempts to open his country's market to imports. GATT officials said the man was hospitalized and was out of immediate danger.