Media General Inc. posted a third-quarter net profit of $ 1.9 million (7 cents a share).For the same period last year, the company posted a net loss of $ 78.8 million ($ 3.03). The 1991 results include a write-off of $ 74.3 million. Revenues for the period were down 2% to $ 139.9 million vs. a year ago. The company said third-quarter revenues and operating profits were paced by its cable television units. Media General said newspaper and broadcast television revenues were “essentialy flat” with those of the year-earlier period , while newsprint revenues dropped because of depressed prices.