Peladeau has insisted he was only trying to keep Mel's Cite du cinema in Quebec hands.
"My action was solely motivated by my belief in the importance of keeping in Quebec hands the control of one of our companies, especially since Mel's studios had benefited in the past from public finances," he said on Facebook.
"There was never any question of favouring Quebecor."
Peladeau has been criticized recently for refusing to sell his shares in Quebecor, which was built by his father, if he becomes PQ leader.
Economic Development Minister Jacques Daoust said he was surprised by Peladeau. He said Peladeau asked him to intercede to maintain the Quebec ownership of Vision Globale, which owns Mel's and was being eyed by Quebecor and an American company.
The Liberal cabinet minister, who was aware that Quebecor had made an offer to purchase Vision Globale, said Peladeau raised the matter with him at a legislative commission which was reviewing spending by his department. Daoust said he did not think that was the place to discuss an ongoing transaction.
Daoust made his comments Friday after Montreal's La Presse reported that Peladeau made a similar intervention with Investissement Quebec in May, shortly after he was elected to the legislature, and at the national assembly in July.
Investissement Quebec is the province's investment arm.
"He asked that a Quebec company be given preferential treatment: 'Go do something for Quebec society','' Daoust said. "I don't have the exact text but it comes down to that.
"Between you and me, one would not think this fellow would ask that question — not knowing what he was doing — not knowing that Quebecor had made a submission."
Peladeau defended himself on his Facebook page.
"There was never a question of favouring Quebecor," he said. "During the numerous years when I had the privilege of heading Quebecor, I knew hundreds of company directors.
"I wanted to use this experience to promote Quebec's economic interests."
Peladeau also offered an apology in advance if he violated the code of ethics of members of the national assembly.
"If I put myself in a situation where there's the appearance of conflict of interest involving the code of ethics, I apologize," he said.
Peladeau said that he's waiting to hear from the ethics commissioner.