US telecom titan Verizon is shunning Google's nascent smartphone wallet, saying the technology reaches too deep into handsets for comfort.

Verizon asked the Internet giant not to include the payment feature on new Android-powered Samsung Galaxy Nexus smartphones tailored for the carrier's network, Google said in response to an AFP inquiry.

Verizon spokesman Jeffrey Nelson said that the carrier was not blocking Google Wallet from Galaxy Nexus smartphones but was "continuing our commercial discussions with Google" regarding including the technology in handsets.

Verizon maintained that its reservations stem from the fact that Wallet requires access to secure chips deep in smartphones.

"Google Wallet does not simply access the operating system and basic hardware of our phones like thousands of other applications," Nelson said.

"Instead, in order to work as architected by Google, Google Wallet needs to be integrated into a new, secure and proprietary hardware element in our phones," he added.

Some industry insiders suspect that Verizon shunned Google Wallet because it is working with other US telecom firms on a competing smartphone NFC payment system called Isis.

A pair of US consumer advocacy groups weighed in on Wednesday, saying Verizon was using its hold on mobile service subscribers to keep them from reaching for Google Wallet.

"Verizon shows no hesitation in using its gatekeeper position over its subscribers to restrict or block applications that compete with its own offerings," Free Press policy director Matt Wood said in a statement.

"Verizon should stop pressuring third parties, including its own business partners, into removing competing applications from consumers' hands," Wood said.

Free Press and consumer group Public Knowledge cited Verizon's move as evidence that stricter "net neutrality" regulation is needed to keep the Internet landscape free and fair.

Google in September opened Wallet to the public, clearing the way for customers to pay at participating shops using Google Nexus S 4G smartphones on the Sprint telecom network and promising more Android handsets to come.

Google Wallet uses a near field communication chip embedded in a phone to allow a user to "tap-and-pay" for purchases at a checkout register equipped with the PayPass system from CitiMasterCard.

Chips essentially transmit credit card details to sensors at checkouts to consummate purchases.

Customers can also use a Google Prepaid card to pay for purchases, topping up the Google card with any payment card, and take advantage of Google Offers, the Mountain View, California-based company's online discount coupon program.

NFC technology is being tested or used in a number of countries already, notably France, but Google Wallet was the first to bring it to the United States on a potentially large scale.