The parent company of the npower Championship outfit have on Tuesday confirmed the interest to the Hong Kong Stock Exchange.
They said in a statement: "The company has been approached by two prospective buyers to explore the possibility of buying Birmingham City FC."
Although Blues are not officially up for sale, chief executive Peter Pannu announced earlier this year that City were keen for new investment, while club president Carson Yeung is awaiting trial following allegations of money-laundering.
The two unnamed parties have entered into confidentiality agreements with the club.
Reports have suggested that former QPR chairman Gianni Paladini is in pole position to buy Blues.
Meanwhile, Birmingham are set to sign experienced midfielder Papa Bouba Diop on a short-term deal.
The club confirmed the 34-year-old has agreed terms with Blues and passed a medical but they are waiting on a visa application before a one-month deal is completed.
Former Senegal international Diop, who helped West Ham to promotion to the Barclays Premier League last season, has impressed on trial at St Andrew's.
He has also played in England for Fulham and Portsmouth, with whom he won the FA Cup in 2008.