A dispute over ownership of the trademark for the popular iPad computer tablets is escalating in China.

U.S.-based Apple Incorporated, the world’s most valuable company, manufactures the iPad in China. But its legal fight with a financially-troubled Chinese company, Proview Technology, over use of the iPad name threatens Apple’s ability to continue exporting it for sales in the U.S. and other major markets around the globe.

The iPad tablets enjoy widespread popularity among technology-conscious Chinese. But in recent days, authorities in several cities have seized the hand-held computers from Chinese retailers as the trademark dispute remains unresolved. Proview has sought Chinese government help in investigating alleged trademark violations in dozens of cities and to prevent exports and imports of the iPad. But the product remains on many store shelves and available for sale.

Apple and Proview both claim their respective positions are backed by court rulings or legal contracts.

Proview registered the iPad trademark in China in 2001, but Apple says that several years ago it bought Proview’s worldwide rights to the trademark in 10 different countries from an affiliate of the firm in Taiwan. Apple says Proview has failed to comply with the agreement and won a judgment in a Hong Kong court giving it the Chinese rights.

But Proview contends that its Shenzen-based unit holds the iPad rights on the mainland. Proview won a Shenzen court decision in November on use of the trademark, but Apple is appealing that verdict.

Chinese media have reported that Proview is deeply in debt and needs to win the trademark fight with Apple in order to pay its creditors. The company’s chairman said in 2010 that the firm is “in big financial trouble and the trademarks are a valuable asset.”