China Unicom <0762.HK>, one of China's top three mobile carriers, has reached a preliminary agreement with Apple for the exclusive sale of its iPhone handset in China for three years, the official Shanghai Securities News reported on Tuesday, however a China Unicom official said a formal deal had not been reached.

Discussions are still ongoing, we have not reached any formal agreement, said Sophia Tso, a spokeswoman for China Unicom.

An Apple spokeswoman declined to comment.

The newspaper said the deal did not include revenue sharing arrangements that media reports said had become a sticking point in discussions between Apple and Chinese mobile companies.

The U.S. company insists on a revenue-sharing model with its cellular partners that offer iPhones, but media reports have said Beijing objected to them.

Under the agreement, China Unicom will purchase iPhones from Apple for 3,000 yuan each and guarantee annual sales of 1 million to 2 million units and at least 5 billion yuan ($732.1 million) in annual revenue, the newspaper said.

China Mobile <0941.HK>, China's dominant mobile carrier, had also been in talks with Apple to sell the iPhone in China, but the newspaper said the talks had broken down.

As of 0642 GMT, China Unicom shares were up 1.4 percent on the Hong Kong Stock Exchange.

(Reporting by Melanie Lee; Editing by Chris Lewis)