Nina Bracewell-Smith, Arsenal's fourth biggest investor, last month put her stake up for sale, appointing U.S. private equity firm Blackstone Group to find a buyer.
Interested parties in the stake include suitors from Europe, North America, China, the Middle East and Africa, said the source, who asked not to be named and refused to disclose any of the parties. He said any resolution on the sale was unlikely for at least six weeks.
Bracewell-Smith's move stoked speculation the club's two big investors - U.S. sports tycoon Stan Kroenke and Russian steel magnate Alisher Usmanov - could make a bid for control.
Usmanov's investment vehicle Red & White Holdings has refused to rule out making a move to add to its existing 26.4 percent holding.
Kroenke owns a 29.9 percent stake. Daniel Fiszman is the third biggest investor with a 16.1 percent stake, according to the club's website.
If any of the top trio bought Bracewell-Smith's stake it would lift them over the 30 percent threshold which requires a formal offer to be made for the business under City takeover rules.
Arsenal finished third in the just completed 2009/10 Premier League season, behind Chelsea and Manchester United.
