Apple is courting owners of US television networks, including CBS and Walt Disney, in the hope of launching a subscription television service over the internet by next year, people familiar with the discussions said.

The service is expected to be offered over Apple's iTunes digital entertainment store, which sells movies and TV shows, but does not offer them for a recurring monthly fee.

The debut of the service is among other entertainment and news services that the maker of the iPod and iPhone could offer on the “tablet” computer it is widely expected to launch imminently.

Magazine publishers Time Inc and Condé Nast have created prototype digital editions of their magazines for a new generation of handheld tablet devices from companies including Hewlett-Packard, Samsung and potentially Apple.

Apple has contacted other broadcast and cable networks, including Time Warner's Turner Broadcasting System and Viacom, which have so far been unconvinced by Apple's proposal. The computer maker has also courted the book publishing industry, sector executives say.

“The driver behind it [the tablet] will be content,” said Kathryn Huberty, a Morgan Stanley analyst.

Apple is preparing an announcement next month that many anticipate will be the official unveiling of its tablet, but the company has so far declined to confirm the existence of the device. Wall Street analysts expect mass production of an Apple tablet to begin as early as February.

Executives close to the discussions fear Apple's possible TV service could undermine the lucrative economics of the pay television industry, where basic networks such as MTV collect a fee per subscriber from distributors such as cable operators as well as selling advertising.

The business model, honed over three decades, has made cable networks one of the most resilient sectors of the media industry during the recession and was the chief reason why Comcast sought to take control of NBC Universal from General Electric this autumn.

Creating a new subscription service with Apple could upset distributors, these people said.

Apple was said to be offering broadcast networks $2 to $4 per subscriber and basic cable networks $1 to $2 a month, according to a Wall Street Journal report.