DHL has acquired for an undisclosed amount a 49 per cent minority interest and a 24.9 per cent voting interest in Astar Air Cargo of Miami, Florida. DHL also extended its contract with the carrier through 2019.

The stake is just under federal thresholds that restrict foreign ownership of US airlines, reports The Miami Herald.

The acquisition comes four years after the airline, which was known then as DHL Airways, was sold by DHL and a private investor to a group led by former Burger King boss John Dasburg for US$57 million. Astar operates a fleet of 44 aircraft serving US, Europe and Mid-East markets. It directs flight operations out of its Wilmington, Ohio hub with gateways in New York, Los Angeles, and Miami.

DHL did not give any reason for buying back Astar, which it said will handle about a third of DHL's express domestic air services in the US.

"Today's announcement signals DHL's confidence in the capabilities of Astar and the high quality of air cargo services Astar provides to DHL in the US," said Mr Dasburg.

Following the completion of the acquisition, Mr Dasburg and the other senior Astar executives will continue in their current positions, with Mr Dasburg as chairman, president and CEO of Astar. Hans Hickler, DHL Express USA chief executive, joins the Astar board.

This purchase comes after DHL recently made aviation investments to support its US operations. The first of these was the company's investment in Polar Air Cargo to provide express delivery services from the US to Asia. DHL also recently announced orders for six Boeing 767-300ER freighters for use mainly between Europe and the United States. DHL is a member of Germany's Deutsche Post group.