NEW YORK -- Apple for the first time is accepting banged up iPhones as a trade-in from those wanting to upgrade.Until now, Apple offered credit to iPhone owners only if the device had an intact screen and working buttons. Apple hopes that with more leeway, applicable only to iPhone 5 and later models, more people will upgrade to new iPhones.Apple Inc. has told investors that it may book its first revenue decline in 13 years when it reports quarterly earnings in April due in part to weakness in the global economy. But the smartphone market has matured as well after a yearslong streak of blistering hot demand.Apple relies on the iPhone for two-thirds of its revenue.Tech blogs have speculated about an iPhone 7 to be released in the fall with dual cameras and wireless earbuds.Apple pays up to $350 for phones without cracked screens or broken buttons. For damaged phones, it will pay $50 for a 5S, $150 for a 6 and $200 for a 6 Plus.The changes, first reported on the tech blog 9to5Mac, were confirmed Friday by Apple spokesman Nick Leahy.