VIENNA - Austria's sensor specialist AMS lowered fourth-quarter revenue outlook by 15 percent, pulled down by demand changes from a major customer, becoming the latest Apple chip supplier to trim its outlook.

In its earnings this month, Apple shocked investors with a lower-than-expected sales forecast for the holiday shopping quarter, prompting suppliers including Lumentum to slash their forecast.

Like Lumentum, AMS supplies Apple with software components needed for its FaceID technology in the latest generation of iPhones. AMS also does not identify Apple as its customer, but analysts estimate that the U.S. giant accounts for 40 percent of the Austrian group's sales.

The Swiss-listed firm said "as a consequence of the changes in customer demand" it now expects revenue to come in between $480 million and $520 million in the three months through December, instead of $570-$610 million it forecast last month.

The adjusted operating margin for the quarter is now expected to reach the low to mid-teens percentage range, AMS said late on Wednesday. Its previous guidance was for the margin to rise to 16 percent to 20 percent.

AMS posted a third-quarter revenue of $479.6 million and an adjusted operating (EBIT) margin of 13 percent.

(Reporting by Kirsti Knolle; Editing by Sherry Jacob-Phillips) ((kirsti.knolle@thomsonreuters.com; +43 1 53112 255; Reuters Messaging: kirsti.knolle.thomsonreuters.com@reuters.net www.reuters.com))