General Electric Co., buoyed by new orders in its aircraft engine and power systems divisions, on Tuesday reported a 12 percent profit gain for the first quarter. GE reported earnings of $950 million in the three months ended March 31, up from $849 million in the first quarter of 1989. Earnings per share were up 13 percent, to $1.06 from 94 cents. Revenue rose 6 percent to $12.6 billion in the first quarter of this year from $11.9 billion a year earlier. ``Very strong earnings improvements were reported by GE Capital, Power Systems and Aircraft Engines,'' said GE chairman John F. Welch Jr. Other divisions with higher earnings included lighting, medical systems, transportation systems, and electrical distribution and controls. He said new orders for power generation were up 60 percent from the first quarter of 1989, while orders from the company's medical systems division were 25 percent ahead of last year. The company reported a total backlog of $35 billion in the aircraft engine division, following new orders from Lufthansa and from Aeroflot, the Soviet national airline. GE said operating profit from its major appliances division was even with last year, while profit and revenue from its broadcasting arm, NBC, were ``somewhat below'' the first-quarter figures in 1989. Operating profit from its materials division was down considerably, which the company attributed to slower demand for cars, appliances and housing. GE said growth in earnings per share was slightly higher than net earnings because of a $10 billion share repurchase program announced last year. Under the program, the company bought back 11.6 million shares for $728 million in the first quarter, bringing total shares acquired to 15.3 million, for a total $963 million, since the program began in November 1989.