NEW YORK (Reuters) - Stonepeak is in advanced talks to acquire Air Transport Services Group ( ATSG ), a provider of aircraft leasing and cargo transportation services, for about $3.1 billion including debt, people familiar with the matter said on Sunday.

The New York-based investment firm is expected to pay $22.50 per share for the company, known as ATSG, representing a premium of nearly 30% to its closing price on Friday, the sources said, requesting anonymity as the discussions are confidential. 

If the talks conclude successfully, the deal could be announced as early as Monday, the sources added. 

Stonepeak and ATSG did not immediately respond to requests for comment.

With factory-to-home retailers like Temu, Shein and others driving up online shopping traffic and brick-and-mortar retailers offering consumers faster delivery times, moving cargo by air has become a vital part of logistics for many corporations. This has boosted the prospects of freight operators like ATSG, making them attractive takeover targets. 

Founded in 1980, ATSG traces its roots to an express freight operator known as Airborne Freight Corporation. In 2003, DHL acquired Airborne's ground operations, excluding the airline and aircraft maintenance operations that eventually became ATSG. 

The Wilmington, Ohio-based company, which counts online retailer Amazon ( AMZN ) as one of its key customers, is a leading lessor of mid-sized freighters, with a fleet of 134 aircraft that includes Boeing 767 and Airbus A321 jets. 

It also provides air cargo transportation and aircraft maintenance services to domestic and foreign airlines and currently has 5,300 employees, according to its website. 

For the quarter ended June 30, ATSG reported an 8% decline in revenue to $488 million and swung to a pretax loss of $7 million, as some key customers leased fewer aircraft. The company said it expects a pickup in demand in the coming quarters as macroeconomic conditions improve.

ATSG is scheduled to report its third-quarter earnings on Friday.

New York-based Stonepeak, which primarily focuses on the infrastructure and real estate industries, has about $70 billion of assets under management, according to its website.

Last year, Stonepeak agreed to acquire container lessor Textainer Group in a deal with an enterprise value of $7.4 billion. Stonepeak is also an investor in cold storage warehouse operator Lineage, whose shares started trading in New York following the company's initial public offering in July.