Zenith Electronics Corp. of Glenview, Ill., reported...

Zenith Electronics Corp. of Glenview, Ill., reported a profit in the first-quarter, compared to a loss in the same period last year, on a 36% rise in sales. The significant increase in revenue over last yearwas due principally to the continuing high level of computer-products sales, a spokesman said. The cable-products business recorded an improvement in operating results over 1986 and was profitable for the quarter, the spokesman added.