AT&T Inc said on Monday delays in activating service for customers of Apple iPhone had been mostly resolved. About 2 percent of those who bought iPhones since they went on sale Friday faced delays in activation with AT&T, the exclusive U.S. service provider for the widely anticipated cell phone, according Reuters reports, citing sources familiar with the matter.

By Monday, those issues were mostly resolved, AT&T spokesman Mark Siegel said.

"We have resolved nearly all of the issues and we feel confident this is behind us now," Siegel said. "One by one, we worked to resolve (the problems) and now nearly all of them have been resolved."

Activation delays stemmed from large customer volumes and problems with customers trying to transfer corporate cell phone accounts to personal iPhone service accounts, AT&T said on Sunday.

AT&T said that iPhone sales for the weekend were the strongest of any device in the company's history.