GENCORP <GY> 1ST QTR OPERATING EARNINGS ROSE GenCorp said its first quarter earnings from operations rose four pct as sales increased six pct to 650 mln dlrs from 614 mln a year earlier. However, the company reported net income declined to 17 mln dlrs, or 77 cts a share, in the quarter ended February 28 from 19 mln dlrs, or 84 cts a year earlier. This year's net included 700,000 dlrs from the sale of assets while last years was increased 3.0 mln dlrs by such sales. GenCorp said lower operating profits for the tire and plastics and industrial products segments were essentially offset by higher wallcovering results.