Comcast, the largest U.S. cable operator, said Tuesday that it is upgrading its residential speed tiers in anticipation of offering new online products later this year.

The company said its current 3Mbps downstream / 256kbps upstream tier will be automatically moved to 4Mbps / 384kbps. Comcast's 4Mbps downstream / 384kbps upstream tier will be upgraded to 6Mbps / 768kbps. There will be no additional charge for the upgrades, Comcast said.

Comcast said the upgrades will prepare subscribers for broadband applications in six key areas of customer interest: communication, music, movies, gaming, sports and "kids". Customers will be automatically upgraded and won't be required to download any special software, Comcast said.