Developer Harry Macklowe is now trying to sell part of his company as a new tactic to save his fortune and his prized GM Building from creditors.

Sources close to the matter tell The Post that discussions are underway with several US and foreign backed “players” to buy as much as a 50 percent stake in Macklowe Properties. News of the talks was first reported yesterday by trade newsletter Real Estate Alert.

Macklowe’s son Billy, president of Macklowe Properties, has been leading the negotiations that started at the top of the market last year when they paid nearly $7 billion for seven Midtown trophy office buildings that had been part of the Equity Office portfolio.

But funds to buy them were raised by mortgaging and pledging other personal assets and properties – including the GM Building on Fifth Ave. – to Deutsche Bank and Fortress Investment. The short-term financing is now overdue.

In an agreement reached with Deutsche Bank, those buildings are now on the market and the Macklowes hired CB Richard Ellis and Citigroup to also sell a stake in the $3 billion GM Building.

But the GM bids have come up short. Sources say that with help from CBRE, the Macklowes are now trying to raise more funds by giving up a piece of all their empire – which includes more office and apartment buildings.

Macklowe desperately needs the cash to block other creditors from seizing his other assets, including his homes in Manhattan and the Hamptons, his contemporary art collection and his beloved 112-foot yacht, Unfurled.

Macklowe bought the GM building in 2003 for $1.4 billion but has increased the debt on it to $1.9 billion after taking cash out.

Aside from the legendary Apple store, the GM Building houses a slew of high-profile tenants, including hedge fund Perry Capital, billionaires Carl Icahn, Thomas H. Lee and Ted Forstmann, and law firm Weil Gotshal & Manges.