Martin Marietta said its first-quarter net rose...

Martin Marietta said its first-quarter net rose 71% from the same period of 1985. Operating earnings were modestly higher. The company said earnings for the 1986 quarter included a gain from the sale of a portion of it equity position in a California biotechnology company, Chiron Corp. A recent U.S. Tax Court decision, which had the effect of reducing capital gains taxes, also aided earnings.