The Quebec government's campaign for separation from Canada has prompted a major business exodus from the French-speaking province, according to a Canadian government report issued today.

The report said that 91 Canadian companies or subsidiaries of American companies had moved their corporate headquarters out of Quebec in the four months since the separatist Parti Quebecois came to power.

Prime Minister Pierre Elliott Trudeau told a press conference today that he "implores and beseeches" companies in Quebec not to play into separatist hands by "stampeding" to English-speaking Canada.

He called the press conference to denounce the Quebec government's first major practical move toward separatism -- a bill introduced in the Quebec National Assembly yesterday making French the only official language of the province.

The tough new language charter rejects Trudeau's concept of Canada as a bilingual country in which English and French share equal status.

The Quebec language charter says that every company, regardless of size or ownership, can be required to conduct its operations in French, forcing the hiring of French-speaking employees or the teaching of French to English-speaking employees.

Initially, the measures would apply only to companies with 50 or more employees, but a powerful new agency, the Office of the French Language, could also force smaller companies to comply.

The Quebec government's move comes as Trudeau has stepped up his counterattacks against it. For the past week, he has been making statements describing the Parti Quebecois as the "internal enemy."

Today Trudeau called the language charter "a regressive denial of the historic righs of English-speaking Quebeckers," and called on opponents of separatism to speak out against it inside Quebec. "The best way to insure a separatist victory is not to stay and fight but to run away," he said.

Quebec Premier Rene Levesque called the moves and threats of moves by big corporations "blackmail."

Earle McLaughlin, president of the Royal Bank of Canada, the country's largest bank responded, also using the word "blackmail." He said the Royal Bank will move its headquarters out of Montreal, Quebec's most important city, if the province moves away from the rest of Canada.

Levesque can count on a comfortable Parti Quebecois majority in the legislature to gain fast approval of the language charter. But the Trudeau government in Ottawa is already talking about overruling the charter on the grounds that it violates the British North America Act, Canada's 110-year old constitution.

The Act says both English and French are the official languages of Quebec, and it guarantees certain language rights to French speaking Canadians outside of Quebec.

The charter would even ban the sale of children's toys or games that require the use of English or any language other than French. It makes French the only official language of all of the province's institutions, schools and businesses.

The charter claims that French has always been the province's sole language, ignoring the dominant economic contribution of Montreal's large English-speaking business community.

The report on the business exodus from Quebec was issued by the Federal Corporate Affairs Department, a Cabinet-level agency.

Its list of 91 companies does not include any major corporate names, but business observers consider it only a matter of time before internationally known companies join the exodus.

During the election campaign, multimillionaire-Charles Bronfman, the head of the huge Seagrams distilling company, threatened to take his business and his baseball team, the Montreal Expos, out of Quebec if the separatists won. But Bronfman apologized for his threat and withdrew it after the Parti Quebecois victory.

Quebec has a population of about 6 million, of which about 49 million speak French as their first language. of these about 3.5 million speaks only French. The total population of Canada is about 23 million.

The school sections of the charter caused an uprear among English-speakers in Quebec, particularly within the province's large Italian community, when they were outlined in a Quebec-government policy statement several weeks ago. The charter says that after a transitional period all children must go to French-language schools except those with a parent who received primary education in English.

The charter is seen in Ottawa as another blow to Trudeau's bilingualism program, which was already in trouble. The program guarantees Canadians across the country the right to deal with the deferal government in either English or French. It has meant extensive and costly retraining of English-speaking bureauerats.

The program has caused widespread resentment outside of Quebec among English-speaking Canadians, who, Trudeau says, "have the misconception that French is being rammed down their throats."

The language charter and the campaigning by both Trudeau and Levesque are seen as a prelude to Levesqye's promised referendum, to be held within the next two years, asking the province's people whether they want independence.

As Trudeau spoke in Ottawa today, U.S. Ambassador Thomas Enders was conferring with Levesque in Quebec City. An embassy official said the meeting had nothing to do with the language charter or separatism but was one of a series of meetings Enders is having with all provincial premiers to discuss Canadian-American relations.