ENTERTAINMENT - Apple won't add NBC's fall shows to iTunes lineup - A power struggle escalates. Timing could be bad for the tech firm.

Apple's decision not to sell new episodes of "Heroes," "30 Rock" and other NBC series marked the latest salvo in the tug of war between the technology giant and the entertainment industry, which is increasingly unsettled by Apple's growing clout.

NBC Universal notified Apple late Thursday that it would not renew its contract to sell digital downloads of its television shows through iTunes when the agreement expires in December. Apple retaliated by saying Friday that it wouldn't sell any shows from the fall season.

"There is probably a concern that Apple has become too dominant and too powerful for many parties here," Jupiter Research analyst Michael Gartenberg said. "This is a power struggle."

If the two companies can't overcome concerns about pricing and anti-piracy measures, Apple plans to yank all NBC shows off the service when the agreement ends, according to people familiar with the situation.

The spat with NBC aired at an inconvenient time for Apple. Chief Executive Steve Jobs is expected to showcase new video-playing iPods at a news conference Wednesday.

Apple said NBC's demands would have caused the price of a TV episode to rise to $4.99 from $1.99.

"We are disappointed to see NBC leave iTunes because we would not agree to their dramatic price increase," said Eddy Cue, Apple's vice president of iTunes. He left open the possibility of an eventual resolution.

NBC, which is launching an initial version its own online video service called Hulu.com with News Corp. in October, disputed Apple's claim. The New York media company attributed the disagreement to Apple's unwillingness to let NBC package together shows with variable pricing.

"It is clear that Apple's retail pricing strategy for its iTunes service is designed to drive sales of Apple devices, at the expense of those who create the content that make these devices worth buying," NBC Universal spokesman Cory Shields said.

Piracy also worries NBC. The media giant contends that Apple is doing too little to prevent iPod owners from filling the portable players with unauthorized copies of TV shows and movies.