Comcast Corp. may consider selling smartphones as part of a wireless service that would compete with major U.S. carriers, chief executive officer Brian Roberts said.

"We've experimented with that before," Roberts said at the Business Insider Ignition conference Tuesday. "Hasn't been a huge success in the past."

The nation's biggest cable company is evaluating whether to enter the maturing cellular business. Asked if Comcast could sell phones as part of a wireless offering, Roberts said, "We might."

The Philadelphia-based company activated a deal with Verizon Communications Inc. in October to sell wireless service on Verizon's network. Roberts said that Comcast is exploring a similar relationship with Sprint Corp. "and others."

The cable giant, in deciding to invoke the agreement with Verizon, is seeking new sources of revenue as consumers ditch traditional TV packages, and competitors such as AT&T Inc. and Charter Communications Inc. get bigger through acquisitions.

Comcast would try to be the first successful cable mobile virtual network operator, or MVNO - a concept pioneered by Virgin Mobile UK in 1999 in which a company buys capacity on other carriers' networks and resells services under its own brand.

Comcast would offer a hybrid cellular and WiFi service, using Verizon's network and the cable company's millions of WiFi hot spots.

The entry of Comcast in the market would come at a time when Verizon and AT&T, the top two U.S. carriers, are already under pressure from smaller rivals such as T-Mobile US Inc., which is winning customers by cutting prices and doubling data allotments.

"We have been looking at our relationship with Verizon and Sprint and others, where we have the right to wholesale the network and marry it with our WiFi," Roberts said. "We're going to experiment in that area."