That would include companies in the banking, transportation and telecommunications sectors.
"The part of our economy which is the responsibility of federal organization is very important in Quebec," said Premier Pauline Marois on Thursday.
The proposal was first raised by Language Minister Diane De Courcy last December, when Bill 14, an act to amend the French language charter, was first introduced.
However, the idea appeared to have fallen by the wayside.
"I don't understand them," said Coalition Avenir Québec critic Nathalie Roy, demanding to know why the proposal was never raised during the recent public hearings into Bill 14.
"That's a little insulting because we spent 8 weeks, and we never talked about it," Roy said. She said groups and businesses which would be affected by such a change were never given an opportunity to appear before the committee reviewing the proposed legislation.
The Liberals, who oppose any toughening of language laws, say there is no reason to crack down on federally regulated businesses, except to play politics.
"I think whenever they see the word 'federal' they break out in a rash," said Liberal MNA Geoffrey Kelley. "So I think there's some of that. If they can provoke a fight with Ottawa, that seems to be something they're quite good at."
A spokesperson for De Courcy said although the minister mentioned the federally regulated businesses in her Bill 14 speech, she never intended to make it part of the law.
Instead, the plan is to simply have the Treasury Board implement the new rules.