TANDY <TAN> 3RD QUARTER REVENUES UP 12 PCT Tandy Corp said consolidated sales and operating revenues for the third quarter, ended March 31, totaled nearly 776.0 mln dlrs, up 12 pct from 693.4 mln dlrs last year. The company said third quarter earnings will be released in the latter part of April. Tandy said March sales and oprating revenues totaled 164.4 mln dlrs, up 11 pct from March 1986's 238.8 mln dlrs. It said U.S. retail operations revenues rose to 225.8 mln dlrs last month from 202.7 mln dlrs a year earlier. Sales of U.S. stores in existence more than one year increased 10 pct.