Morris troupe bids US farewell. Mark Morris, one of the most inventive forces in contemporary American dance, moves his company to Europe this fall. In interviews below, the dancer/choreographer and members of his company talk about the reasons. Elsewhere on this page, critics review two of the Mark Morris Dance Group's last US programs.

The Mark Morris Dance Group's recent farewell tour showed once again why the inventive, taboo-busting Seattle choreographer is considered a Wunderkind in American dance. In the fall, he and his company will move to Brussels, where they will be the official dance company of the Th'e^atre Royale de la Monnaie. They will be supported by the Belgian government for at least three years. This fact may have made the tour performances poignant for fans. But the company danced as if it were business as usual for them - brilliantly, but without farewell gestures. A `tremendous opportunity' Asked why the company is leaving, Nancy Umanoff, its managing director, says, ``We're not leaving because this [their situation in the US] is bad, but because it's a tremendous opportunity.'' If the offer hadn't come when the theater's director met Morris by chance in Stuttgart, ``we wouldn't be searching for another one,'' she said.

The Belgium post will, however, be a change from the company's present situation. ``The important thing is the way Europeans see art as a necessity; so it's state supported. It will be less of a struggle for us.''

The company will have three theaters to perform in, a permanent home with ample rehearsal space, and, most important to Morris, a live orchestra to dance to. It will grow from 13 dancers, who had been working 30 to 40 weeks a year and making up the balance with unemployment benefits or working for other companies, to 20 fully-salaried dancers. The company's annual budget will be $1.5 million.

The circumstances around the Boston performance point up the difference between state arts support and the way it is garnered in the US. For these performances, the Morris Group waived its usual performance fee to benefit Dance Umbrella, which presented the concert. Dance Umbrella had not only produced Morris's work early on; it had commissioned ``Mythologies,'' an ambitious full-evening work to a commissioned score.

When no producer could be found to put on ``Mythologies'' in New York, the company's general manager, Barry Alterman, decided to produce it himself, raising money from friends.

One who came forward was Jeremy Alliger, Dance Umbrella executive director, putting up money from his own savings.

Morris is philosophical about the financial aspects of producing dance. ``I think they have nothing to do with the creative process,'' he says bluntly and frankly. ``They can help or hinder production'' of a work, but ``in the end you'll do it anyway, whether you have a budget or not.''

Asked if freedom from dependence on box-office receipts will tempt him to be less aware of pleasing an audience, he says somewhat indignantly, ``I have never worried about marketing. I don't have a publicist, and I don't schmooze with rich people.'' When he choreographs, ``I have me in mind. I like to see shows; I like to see good dancing; I like good music.'' He attributes his critical and popular success to the fact that ``I'm very particular about what I like to see.'' Handel oratorio in Brussels

His first production in Brussels will be a work to Handel's oratorio ``L'Allegro, Il Penseroso, ed Il Moderato.'' a full-evening work that had been planned for the Boston Ballet but was later scrapped because Boston Ballet artistic director Bruce Marks felt a new work to start out the year would lose business for the company.

Morris seems determined not to let his good fortune go to his head. He says, ``What doesn't change is: It's still really hard to make up a piece.''