Associated Press reports that a Chinese court has ruled against Apple in its ongoing trademark dispute with Proview Technology over the rights to the "iPad" trademark in that country, deciding that distributors should halt sales of the iPad in China. The impact of the ruling is, however, unclear as the lawsuit is just one of many Proview has filed against Apple in its efforts to extract as much as $2 billion for the trademark rights.

Xie Xianghui, a lawyer for Shenzhen Proview Technology, said the Intermediate People's Court in Huizhou, a city in southern China's Guangdong province, had ruled on Friday that distributors should stop selling iPads in China.

The ruling, which was also reported widely in China's state media, may not have a far-reaching effect. In its battle with Apple, Proview is utilizing lawsuits in several places and also requesting commercial authorities in 40 cities to block iPad sales.

Apple Inc. said in a statement Monday that its case is still pending in mainland China. The company has appealed to Guangdong's High Court against an earlier ruling in Proview's favor.

Meanwhile, IDG News reports that Apple sent a letter to Proview today threatening a lawsuit over defamation charges. Apple had previously won a case over the trademark rights in a Hong Kong court, and Apple's threats claim that Proview has issued false public statements regarding the dispute.

On Monday, Apple sent a letter to Chinese display vendor Proview, demanding its founder Yang Rongshan cease releasing what it said was false information to the media. Apple then warned it would sue for damages caused by "defamatory statements."

"It is inappropriate to release information contrary to the facts to the media, especially when such disclosures have the effect of wrongfully causing damage to Apple's reputation," said the letter, which was provided by a person familiar with the matter.

Apple claims that a shell company it set up for the purpose of anonymously acquiring intellectual property rights purchased the iPad trademark rights in China and a number of other countries from Proview in 2009 for $55,000. But Proview later reported that the subsidiary making the deal did not hold the Chinese rights and demanded that Apple pay $10 million before a different subsidiary would transfer the rights.

The Hong Kong court ruled last year that the various Proview subsidiaries colluded in an effort to extort millions of dollar out of Apple, a figure that has now risen to $1-2 billion as Proview has continued to press its case. Chinese courts have so far sided with Proview, however, with Apple continuing to appeal there using the Hong Kong ruling to demonstrate the strength of its case.

Update: Financial Times clarifies that the court ruling today specifically related to a singel retailer, Sundan. While the impact of the decision is limited due to its effect on a single retailer in a single city and the fact that it can still be appealed by Sundan, it may provide Proview with leverage as it pursues other lawsuits against resellers to try to halt the flow of iPads and force a settlement from Apple.