Apple Inc unveiled larger iPhones and watches based on the design of current models on Wednesday, confirming expectations that the company is making only minor changes to its lineup.

Apple wants users to upgrade to newer, more expensive devices as a way to boost revenue as global demand for smartphones levels off. The strategy has helped Apple become the first publicly-traded US company to hit a market value of more than $1 trillion earlier this year.

Apple shares were down 0.9 percent on Nasdaq.

The new phones, based on last year's iPhone X, are named XS and XS Max, based on last year's iPhone X. The new iPhone XS has a 5.8-inch screen size, while iPhone XS Max is 6.5 inch in size, in line with Wall Street expectations.

Philip W. Schiller, Senior Vice President, Worldwide Marketing of Apple, speaks about the the new Apple iPhone XS and XS Max at an Apple Inc product launch event at the Steve Jobs Theater in Cupertino, California, US, September 12, 2018. REUTERS/Stephen Lam

Apple uses the 'S' suffix when it upgrades components but leaves the exterior of a phone the same. Last year's iPhone X - pronounced "ten" - represented a major redesign.

Apple opened its event by saying its new Apple Watch Series 4 range will have edge-to-edge displays, like its latest phones, which are more than 30 percent bigger than displays on current models. The new watch, positioned as a more comprehensive health device, will be able to detect an irregular heartbeat and start an emergency call automatically if it detects a user falling down, potentially appealing to older customers.

Shares of fitness device rival Fitbit Inc fell about 3.7 percent after the Series 4 introduction. Shares of Garmin Ltd lost some earlier gains and were flat in midday New York trade.

Philip W. Schiller, Senior Vice President, Worldwide Marketing of Apple, speaks about the the new Apple iPhone XS and XS Max at an Apple Inc product launch event at the Steve Jobs Theater in Cupertino, California, US, September 12, 2018. REUTERS/Stephen Lam

Shares of optical components makers Lumentum Holdings Inc and Finisar Corp, suppliers that power iPhone X's Face ID feature and the TrueDepth camera technology, were down 1.6 percent and 0.4 percent in afternoon trading.

Executives made the announcement at the Steve Jobs Theater at Apple's new circular headquarters in Cupertino, California, named after the company's co-founder who wowed the world with the first iPhone in 2007.

"There's no real game-changer on the table," said Hal Eddins, chief economist at Apple shareholder Capital Investment Counsel. "It's a matter of getting people to keep moving up."

The company is also expected to unveil a new version of its wireless AirPods earbuds with wireless charging and a wireless mat that will be able to charge several devices at once.

Reuters