For more than two decades, scrappy long-distance carrier MCI has clamped onto AT&T; like a demented terrier on a mailman's ankle and refused to let go. It was MCI's antitrust charges against the old Ma Bell that led to the breakup of AT&T;'s telephone monopoly. Now MCI is joining forces with British Telecommunications--Britain's formerly state-owned telephone company--to form an empire with the clout to go phone-to-phone around the world with AT&T; and other giants.
In what would be the largest foreign buyout of a U.S. company if regulators approve it (an uncertain prospect, given likely resistance from rivals like AT&T;), BT...