When the phone proved to be a hit, Verizon appeared to be left out of the race for versatile phones running programs from third-party developers. Verizon was also not particularly friendly with Google, whose participation in an auction of precious wireless spectrum angered Verizon executives. Google wanted to force the federal government to require carriers to make their networks more open to a wide range of devices and software. Verizon executives were furious, vowing that they would not support the Android operating system.

Image Verizon will begin selling the Motorola Droid X, a challenger to the iPhone, on Thursday. Credit... Jeff Chiu/Associated Press

A year later, Verizon recognized the threat posed by the iPhone and began working with Google and Motorola to develop the first of its Android phones, which it sold under the name Droid, a trademark it licensed from Lucasfilm.

Verizon has since collaborated closely with Google to develop six phones running Android, helping to give Google’s mobile operating system 13 percent of the smartphone market in the United States. In contrast, Apple has a 24 percent share, while Research In Motion, maker of the BlackBerry, commands nearly 42 percent.

T-Mobile and Sprint have also jumped on the Android bandwagon. Matt Carter, president of Sprint’s 4G division, said the company was building a portfolio of smartphones that could run on its fourth-generation wireless network, including the Evo, an Android phone made by HTC.

“Obviously, we would love to have the iPhone, but we feel the HTC Evo is a better phone,” he said.

The success of its Android phones has emboldened Verizon to take shots at Mr. Jobs and the iPhone. A recent ad slyly referred to the controversy over the iPhone 4’s antenna design in boasting that the Droid X “allows you to hold the phone any way you like and use it just about anywhere to make crystal-clear calls.”

“Verizon is behaving as if it’s not going to get the iPhone anytime soon,” said Charles Wolf, an analyst at Needham & Company. “The signal I’m getting from the intimacy of Google and Verizon is that it is certainly an engagement, if not a marriage.”

Reports from analysts and the news media have predicted, with almost comic regularity, an iPhone debut on Verizon in the next week, next month or next year. Representatives for Verizon and Apple declined to comment on the matter.