American Telephone & Telegraph Co. plans to...

American Telephone & Telegraph Co. plans to nearly double the size of its digital long-distance network by the end of 1991, the company’s chairman said. AT&T; Chairman James E. Olson also said that the telecommunications giant plans to invest $3 billion in its worldwide network next year and a similar amount in 1989. The new plan will expand AT&T;’s domestic digital network to 60,000 miles by 1989 and to 67,000 miles by 1990. Worldwide, the company’s digital network will grow to 74,000 miles in 1989 and to 88,000 miles by 1991.