SAN FRANCISCO (AP) - Apple is expected to showcase three new iPhones on Wednesday, including its biggest and most expensive model yet, as the company seeks to widen the product's appeal amid slowing sales growth.

Most of the buzz is swirling around a rumored iPhone that is supposed to boast a 6.5-inch screen, up from 5.8 inches on the existing iPhone X. If the speculation pans out, the even-bigger iPhone would represent Apple's attempt to feed consumers' appetite for increasingly bigger screens as they rely on smartphones to watch and record video, as well as take photos wherever they are.

Apple also is expected to release an iPhone with minor updates to last year's $1,000 model and another version made of cheaper materials. Wednesday's event is being held at Apple's Cupertino, California, headquarters.