In the first casualty of the current players strike, the management of the Utah Symphony and officials of the Sundance Institute canceled the orchestra's concert of movie music Friday.

And both sides conceded there may be more cancellations before the strike, which began Thursday, is ended.The concert, which was to be hosted by actor Christopher Reeve, star of the "Superman" movies, was to have been a joint fund-raiser for the symphony and the institute. Earlier in the week a letter from Sundance Institute executive director Thomas L. Wilhite to symphony board president Deedee Corradini and orchestra committee chairman John Thompson asked both sides to reconsider.

"If this concert is canceled . . . there is no guarantee that it could be rescheduled, and certainly no guarantee that we would be successful in securing the same number or quality of artists to donate their time again," the letter said. "Sundance is not taking sides in your dispute. We only ask that the musicians play for the benefit without a contract while both parties continue to negotiate. This would allow the symphony management to not lose ground in their fund-raising efforts, and allow the musicians to show their good faith to the community."

The musicians' response, according to orchestra spokesman Craig Fineshriber, was that "we cannot play the concert or any concert until we have an agreement."

Tuesday the chief negotiators on each side, former Utah governors Scott M. Matheson and Calvin L. Rampton, met in what Matheson described as an informal session, the first since the strike was declared last week.

The musicians reportedly presented a revised proposal seeking more modest salary increases as well as guarantees in working conditions and fringe benefits. Initially they had sought a 20 percent increase over 52 weeks. The board, by contrast, has proposed cuts totaling 5.9 percent to be arrived at through reductions in salary, length of season and/or the size of the orchestra.

"Working conditions, in my opinion, shouldn't be a serious bargaining point,"

atheson said. "We've put in what we think we can live with and what we hope they can live with." Reportedly no new proposal was forthcoming from the board but, according to Matheson, Rampton agreed "the ball is now in their court."

Negotiators for both sides were scheduled to meet Wednesday afternoon with music director Joseph Silverstein.

"I wouldn't want to disparage what movement they might think is there," said the symphony's executive director, Paul R. Chummers, of the redrafted musicians' proposal. "But there wasn't enough to give us any hope on the Sundance thing."

Even though Sundance had begun setting up its projection equipment in the hall Tuesday, Chummers acknowledged rehearsals would have had to begin no later than Thursday with the five conductors scheduled to direct the concert.

At the same time he pointed out that two key rehearsals for Ballet West's season-opening presentation of "Romeo and Juliet" were missed Tuesday, "which means they are going to have to realize we may not be in a position to play for them either." Nor was he optimistic about the symphony's own opening concerts of the season, set Sept. 16-17 in Symphony Hall.

The musicians, for their part, have announced a concert schedule of their own, beginning with a chamber program Friday at Westminster College. Other concerts include two with the full orchestra Sept. 15 and 23 in Kingsbury Hall and another chamber evening at Westminster Sept. 19.

Starting time for each is 8 p.m., with donations welcome.