Chicago

United Airlines is preparing to place an order for 10 of Boeing Co's largest twin-engine jetliners to replace older aircraft plying its longest routes, said people familiar with its plans.

The Boeing 777-300ERs would be the first of that variant bought by United, the world's second-largest carrier, said three of the people, who aren't authorised to speak publicly because talks are private. The deal would have a value of US$3.3 billion based on list prices, though airlines commonly get discounts.