Google Inc. said it plans to launch a U.S. wireless service, raising a new risk of tension between the Internet company and the wireless carriers that support its Android mobile-operating system.

The service would be small-scale and not intended to compete with the four big U.S. national carriers, Sundar Pichai, the Google executive who oversees Android, told an industry conference in Barcelona. Instead, it would be intended to demonstrate technical innovations that carriers could adopt.

However small Google’s entry, the move by the creative and well-capitalized technology company is likely to send ripples through a business long controlled by Verizon Communications Inc., AT&T Inc., Sprint Corp. and T-Mobile US Inc. It is a strong signal that Google’s ambitions extend beyond selling advertising and services over the Internet to influencing how Internet access is delivered.

“You will see us announce it in the coming months,” Mr. Pichai said. “Our goal here is to drive a set of innovations which we think the system should adopt.”

The comments confirmed earlier media reports of the company’s plans. Google has struck deals with Sprint and T-Mobile to resell service on their networks, people familiar with the matter have said. Mr. Pichai said on Monday that Google would team up with carriers to launch the service but didn’t name them. AT&T, Verizon, Sprint and T-Mobile declined to comment.