The international ballet star Vladimir Vasiliev said Tuesday he had accepted an invitation to be the new artistic director of the Bolshoi Theater, ending months of conflicting reports over the leadership of Moscow's famous opera and ballet company.


Confirmed but not yet officially announced by the Culture Ministry, the move is the first in a major government-led shake-up intended to turn around the struggling company and launch an ambitious 10-year, $300 million reconstruction program for the theater.


Vasiliev, a former Bolshoi principal, would be returning after a virtual exile of 10 years from the theater. His appointment, which is to take effect in February, is intended to bring to a close Yury Grigorovich's 30-year rule as artistic director, chief choreographer and ballet-master. Grigorovich, on his way to a rehearsal of "Don Quixote" on Tuesday, dismissed the report. Asked at the theater if he was being replaced, he simply said "no" without elaborating.


Vasiliev declined to comment on Grigorovich's position. "There will be no immediate changes, the cardinal changes can wait until next season since this season's program is already set," Vasiliev said.


One policy he would institute, he said, was to invite many guest performers including outside composers, directors, conductors and choreographers. But while Vasiliev said it was important for the theater to experiment, he stopped short of insisting that radically experimental productions be staged because "it's not essential for the world to see them."


Grigorovich and the Bolshoi Ballet have been criticized for a repertoire largely of recycled classics, and for falling standards and morale among dancers and singers, as the best have left to join theaters abroad.


"The Bolshoi Theater is in such a state it will demand unbelievable courage and strength of will on the part of Vasiliev," Moscow ballet critic Natalya Chernova said.


The appointment, rumored for weeks, was warmly welcomed in ballet circles. "It means the Grigorovich epoch is ending," Chernova said. "It has been rule by the little tsars and the theater must change."


Vasiliev's appointment was decided at top government level, after consultations with the president's administration and members of the State Duma Committee for Education and Culture, said Culture Ministry spokeswoman Natalya Uvarova.


Meanwhile, leading cellist Mstislav Rostropovich said Tuesday he had turned down an offer to head the Bolshoi's collegium, a board of prominent personalities in the music and ballet world and government figures who would oversee artistic standards.


Speaking by telephone during a rehearsal break at the Royal Opera Theater in Stockholm, Rostropovich said he had declined for two reasons: "Firstly, I am not in Moscow very often and it would be too difficult. Secondly, the budget for the theater is only half what is needed."


Vasiliev said he expected the job would be a "heavy cross," and particularly difficult because he would be taking over a theater in deep crisis.


"I took up this offer only because of the presidential decree introducing a contract system to the theater. It is very important, without it the job would be impossible," he said.


President Boris Yeltsin signed a decree in September introducing contracts for all staff at the Bolshoi. The decree was widely welcomed at the time and seen as heralding a new regime of professionalism and accountability at the ailing theater, but it has drawn opposition from some members of the company. Employees have traditionally been assured of a job for life, which the contract system is aimed at ending, although dancers and singers have often suffered from an arbitrary system of favoritism.


Vasiliev and his wife, Yekaterina Maksimova, were both young stars of the Bolshoi but they fell out with Grigorovich in the early 1980s.


Vasiliev, a potential rival as a choreographer, found his work ignored. The couple were refused foreign tours and were finally forced into early retirement from the Bolshoi.


Chernova, the ballet critic, said Vasiliev would have to revive the long-buried creative spirit of the company, suffocated by a bureaucratic atmosphere, poor discipline and low morale among dancers who dare not speak their minds and only think about money.


Marina Nestyeva, music critic for the quarterly Musykalnaya Akademiya, said, "Musically, the Bolshoi has sunk not just to the ground but to below ground level."


The theater is also beset with money problems and housed in a building that is literally sinking into the ground and will require millions of dollars to repair.


Another controversial Bolshoi figure, Vladimir Kokonin, general director of the company, is likely to remain in his post for the foreseeable future, according to sources close to the theater management.


Tuesday morning the ballet workers' committee held a rare meeting of the entire ballet company where many criticized Kokonin's leadership.


"The dirt that the theater director is pouring on the company's reputation now, will take years to clean off," Grigorovich said.


Three dancers, who declined to be identified, said members voted in a secret ballot initiated by Grigorovich on whether to approve Kokonin's directorship, implementation of the contract system and the formation of an outside collegium board.


Depending on the outcome of the vote to be announced Wednesday, Yury Vladimirov, head of the workers' committee, threatened to stage a temporary walkout by the 200-member ballet company.