McDonnell Douglas Corp. is currently talking to several domestic and foreign aircraft makers, including the European Airbus Industrie, about a joint undertaking to produce a new 150-passenger commercial airplane, the chairman of the company said today.

First in remarks to the annual shareholders meeting and later in comments to reporters, Sanford N. McDonnell said the company expects by about June 1 to pick a major partner who will absorb "a significant share" of the development costs.

There is growing airline pressure for a 150-passenger twin jet that utilizes all the latest noise-reduction and fuel-saving technology. Delta Airlines officials recently announced that they would purchase 100 such planes as part of Delta's fleet replacement program, and United Airlines is expected to indicate its interest in a similar plane soon.

McDonnell told shareholders the growing airline interest in a new, comparatively small twin-engine jet could be "an important opportunity" that the company intends to pursue vigorously. But he cautioned that the company will not go ahead with a program unless it is convinced that a substantial market for a plane of that size "really does exist" and will not wane when economic conditions and airline traffic turn upward. The program would not be undertaken "without kickoff orders of sufficient quantity and quality."

McDonnell Douglas would also want to be satisfied that the financial risks of such a program would not be too great, he said. "One possible way of satisfying ourselves on this . . . is to establish [a] risk-sharing relationship with other companies," he noted.

McDonnell said there was a "high" probability that the company's conditions would be met and a decision "to spend the money to make a proposal" on a plane would be made. A decision to actually make the plane wouldn't be made until the airlines "pick our airplane over the competition," he said.

Overall, the company had good news to report to its shareholders. First-quarter earnings were $41.2 million (1.03 a share, fully diluted) compared with $43.4 million ($1.1.) during the first quarter of 1980. While the quarter's earnings were 6 percent below last year's, the year-earlier period contained a $15.5 million gain from a real estate transaction. If that transaction were removed, last-quarter earnings were up more than 47 percent, the company said.

Sales were up 14 percent in the first quarter to $1.6 billion, from $1.4 billion last year. The gain was attributed to an increase of 48 percent in military aircraft sales, only partially offset by a 23 percent decrease in commercial aircraft sales.

McDonnell and other company officials engaged in a lengthly defense of the company's F-18 Hornet and attacked recent criticisms from Washington about rising costs of the fighter plane program as "ridiculous." George S. Graff, president of McDonnell Aircraft Co., said there were "no significant cost problems with the Hornet -- just inflation, inflation yet to come."