SAN FRANCISCO  Facing intense competition from phone makers wedded to Google’s Android software, Steven P. Jobs, Apple’s chief executive, finally plans to make the iPhone available on Verizon Wireless, the largest wireless carrier in the United States.

After more than three years of using only AT&T cellphone networks, Apple is now making a version of the iPhone 4 for Verizon’s network, according to a person who is in direct contact with Apple. Apple and Verizon will begin selling the phone early next year, said the person, who agreed to speak on condition of anonymity because the plans were supposed to be confidential and he did not want to alienate his contacts at Apple.

Apple and Verizon Wireless declined to comment.

The arrival of the iPhone on Verizon, which has long been expected and frequently rumored, could sharply alter the dynamics of the smartphone market in the United States. The iPhone remains the best-selling smartphone. But around the world, many carriers, especially those that do not have access to the iPhone, have been promoting an array of handset models running on Google’s Android software. Collectively, those phones now outsell the iPhone.

This week, Nielsen reported that Android accounted for 32 percent of the new smartphones sold in the United States in last six months. By comparison, the iPhone accounted for 25 percent. The numbers confirm those of other research organizations.