EARNINGS

McDonnell, Rockwell Post Gains: First-quarter profits announced by the two aerospace and defense companies reflected the results of deep cost-cutting efforts that have included the elimination of thousands of jobs. Earnings at McDonnell Douglas would have risen 30% if not for onetime charges last year. The St. Louis-based company earned $134 million, or $3.41 a share, compared to $216 million, or $5.51 a share, during the first three months of 1993. Rockwell International Corp. said earnings increased 13% in its fiscal second quarter, led by strong gains in its largest division, electronics. The Seal Beach-based space shuttle builder reported a profit of $154.7 million, or 70 cents per share, for the January-March period, compared to $136.9 million, or 63 cents per share, a year earlier.