"The reporting by La Repubblica about selling a stake in AC Milan is a complete fabrication. It is wholly untrue," a spokesperson for RedBird said.
RedBird took over AC Milan from US fund Elliott in a 1.2 billion euro buyout.
La Repubblica said it was partly financed through a vendor loan from Elliott worth 560 million euros due next year, plus RedBird's own investment of 681 million euros.
RedBird was now looking to "rebalance its portfolio" by selling "up to 150 million euros of the initial invested capital of 681 million" at base cost, the newspaper added.
They cited a document for potential new investors prepared by US investment firm Washington Harbour on behalf of RedBird, adding that the file "has been circulating in international financial circles since May."
In an earlier statement which stopped short of a full denial, a RedBird spokesperson had told Reuters that Gerry Cardinale, the founder and managing partner of the fund, "does not know Washington Harbour and the document cited by the newspaper is not attributable to him."
Washington Harbour did not reply to a Reuters request seeking comment over the press report.