Delta Air Lines to spend $1 billion on upgrades

Flat-bed seats offer extra legroom and more privacy.

"Rather than invest in new aircraft, Delta will be spending its capital to improve the quality and consistency of the on-board product and efficiency of the aircraft we already own," Delta President Ed Bastian said in a statement.

Delta, which acquired Northwest Airlines in 2008, said the moves also included completing modification of 269 pre-merger Northwest planes to add blue leather seats, updated lighting and better amenities such as more overhead bin space. The carrier also said it would install winglets on more than 170 Boeing planes to extend aircraft range and boost fuel efficiency.

The airline's plans also include renovating and expanding its Sky Club lounge in Los Angeles and introducing Sky Club locations in Seattle, Philadelphia and Indianapolis.