Apple Inc. plans to break with its recent pattern of overhauling the design of its flagship iPhone every two years, and make only subtle changes in the models it will release this fall, according to people familiar with the matter.

Among other things, those people said, Apple’s newest phones will maintain the current 4.7-inch and 5.5-inch displays. Those are the sizes of the larger-display models Apple introduced in 2014, and refreshed with newer models last fall.

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