DUBAI (Reuters) - Qatar Airways placed an order on Sunday for five Airbus A330 freighters as it expands its cargo business.

The Gulf carrier said it had taken out options for a further 8 aircraft, making the deal potentially worth $2.8 billion at list prices.

"Cargo is a strategic part of our business," Chief Executive Akbar Al Baker said after announcing the orders at the Dubai Airshow.

Qatar operates A330 passenger jets and is the launch customer for Airbus's newest jet, the A350.

Al Baker said Qatar Airways was considering upgrading some of its orders for A350-900 models to the larger A350-1000.

He said it would be interested in examining a stretched version of the A350-1000 if Airbus decided to build one.

Airbus sales chief John Leahy, who has floated the possibility of making the 350-seat aircraft bigger as Boeing launches a new 400-seat version of its competing 777, said earlier that Airbus had no plans to go ahead with the idea.

(Reporting by Tim Hepher)