NEW YORK (AFP) - US stocks ended mostly little-changed Wednesday (Sept 7) but the Nasdaq Composite added to its record high, helped by a 0.6 per cent jump in Apple shares after the company unveiled two new iPhones.

Airline shares also surged after several offered good outlooks at a transportation conference.

The Dow Jones Industrial Average finished off less than 0.1 per cent at 18,526.14.

The broad-based S&P 500 was virtually unchanged at 2,186.15.

The tech-rich Nasdaq Composite, which punched through to a new record on Tuesday, added another 0.2 per cent to a fresh high of 5,283.93.

Apple shares got a modest lift after the company revealed upgraded versions of its iPhone and a new waterproof smartwatch.

Allegiant Travel, operator of Allegiant Air, led the airline sector higher with an 8.2 per cent gain after reporting improving revenues based on capacity, Bloomberg said.

Delta jumped 5.7 per cent, United 5 per cent, and American 4.8 per cent, as others in the industry also indicated stronger forecasts.

Computer memory manufacturer Western Digital climbed 12.1 per cent after giving stronger earnings targets for this quarter.

Burrito chain Chipotle Mexican Grill surged 5.9 per cent on news that Wall Street activist investor William Ackman, known to pressure boardrooms for better investor returns, had picked up a 9.9 per cent stake in the company.

Oil driller Apache Corp. jumped 6.7 per cent after reporting a solid oil and gas field discovery in western Texas.

Apache estimated the "Alpine High" discovery contains three billion barrels of oil and 75 trillion cubic feet of natural gas.

Grocery chain Whole Foods Market meanwhile sank 5.3 per cent after a rival, Sprouts Farmers Market, cut its earnings outlook citing downward pressure on prices.