Apple will reinforce sales of the no-strings-attached iPhone 4 by cooperating with several IT distributors, which some analysts believe may put pressure on China Unicom - Apple's exclusive partner in the country.

Three IT distributors - Changhong IT, Beijing Founder Century, ECS Technology (China) Ltd - have been selected by Apple as new outlets for sales of unbundled iPhone 4s, Chinese portal website sina. com reported Monday.

Changhong IT has just signed a contract with Apple to act as an iPhone 4 sales agent in the mainland, an unnamed source in the company told the Global Times on Monday.

The no-strings-attached version of iPhone 4 will be launched soon throughout Changhong IT's sales channels in 18 cities across the country, according to the source.

The other two distributors, Founder Century and ECS Technology (China) Ltd, could not be reached for comment.

Digital China, the largest IT distributor in China, is reportedly not on the list. Repeated calls to confirm media reports went unanswered.

Apple Inc Spokesperson Carolyn Wu could not be reached for comment.

Market watchers said this move is likely to be to the detriment of China Unicom, the largest volume retailer of iPhone 4s in the country.

"China Unicom will be affected, as the increasing number of outlets for Apple's own iPhone 4 sales would certainly dilute that from China Unicom," said Wang Yang, director of China Research at research firm iSuppli.

Apple announced in late September the launch of its new and cool gadget - the iPhone 4 - in the Chinese mainland.

The product went on sale in four Apple Stores in Beijing and Shanghai as well as retail outlets of China Unicom.

China Unicom offers the product with a two-year contract, while Apple Stores sell it unbundled. IPhone 4s sales averaged more than 200,000 units per month since their launch, and roughly 80 percent of sales come from China Unicom, according to Wang.

But given the significant role of telecom operators in the market, the new sales distributors would not have a big impact on China Unicom, said Ji Chendong, a consultant with research firm Frost & Sullivan, said however.

"This action is more of a backup strategy for Apple, which may deliberate on its future expansion in China, as its exclusive agreement with China Unicom winds down early next year," he said.

Analysts also said even with more outlets available for iPhone 4 sales, that cannot solve the shortage in supplies facing the mainland consumers. One key item, the device's touchscreen, are in short supply due to a lack of raw materials. The fact that the US and European markets are Apple's top priority for iPhone 4 supplies worsens the shortage in China, Ji added.