Updated from Sept. 22

Let the asset sales begin.

Delta Air Lines ( DAL) has arranged to sell eight MD-11 aircraft to FedEx ( FDX), TheStreet.com has learned. The deal could net more than $200 million for the airline, buying it time to negotiate wage concessions from pilots as bankruptcy looms.

In a Wednesday morning conference call discussing first-quarter earnings, FedEx management said it would boost its annual capital spending budget by nearly $400 million to $2.1 billion. Execs added that the company would use the money to fund an "opportunistic purchase of eight MD-11 passenger aircraft in excellent condition at attractive prices."

Delta didn't immediately return a call seeking comment, and FedEx declined to comment. But people close to the sale say that Delta could be revealed as the mystery seller by the end of the week.

Indeed, Delta owns exactly eight MD-11s and has them in storage, according to BackAviation Solutions, an aviation consultancy. Michael Allen, operating chief at BackAviation, says Delta seems apt to sell planes, given its financial difficulties.

"FedEx said they were capacity constrained on some business lines and needed to find additional aircraft," adds Helane Becker, airline analyst at Benchmark Co., a New York brokerage. "A few years ago, they bought some MD-11s" from the American Airlines unit of AMR ( AMR) and the United Airlines unit of UAL ( UALAQ.OB), Becker says.

Now, "Delta has the only fleet that's available for sale," she adds. "There's not a lot of MD-11s out there and Delta's are parked in the desert."

According to Allen, six of Delta's MD-11s are more than a decade old and are worth roughly $30 million each. The remaining two MD-11s are between six and eight years old and are valued at nearly $37 million. All told, FedEx will be buying eight MD-11s with a value of between $246 million and $262 million. But the shipping giant will likely get a discount.

"FedEx has over 20% of the MD-11 fleet out there," says Allen, noting the company's MD-11 fleet is easily the largest in the world, more than three times the size of UPS' ( UPS) fleet. "There only so many buyers. If FedEx is buying in volume and is the largest operator of those planes -- we're not privy to the deal -- they'll probably get a discount in excess of 20%."

This would imply that Delta could stand to net as much as $210 million from the sale, helping shore up its cash position as it works to win $1 billion in wage concessions from pilots and restructure $20 billion worth of debt.

On Wednesday, shares of Delta fell 17 cents, or 4.4%, to $3.69.