Apple Inc's recent agreement with China Mobile Ltd, the world's biggest telecom carrier with a user base of 760 million, is a significant start for the two companies' cooperation, according to two of their top executives. Xi Guohua, chairman of China Mobile, compared the company's six-year continuous negotiations with Apple with a long "courtship". After the two companies finally reached a deal on Dec 23, 2013, Xi joked that China Mobile and Apple had entered into a happy marriage. Xi made the remarks at a small news briefing with Tim Cook, Apple's chief executive officer, at China Mobile's Beijing headquarters on Wednesday. According to the December agreement, China Mobile is going to sell the iPhone 5S and iPhone 5C handsets on its fourth generation (4G) network on the Chinese mainland from Jan 17. The contract fee is fixed at 5,488 yuan (907 U.S. dollars) for a 16-gigabyte iPhone 5S handset and shoppers can select a monthly payment varying from 138 yuan to 588 yuan. The number of pre-orders for China Mobile's iPhone devices in a 20-day period starting Dec 25, exceeded 1 million, according to the company. Xi said he was confident sales of the China Mobile version of the iPhones would far exceed the expectations of others. "It's just the start of our cooperation," Cook said. It has been the third time he has paid a visit to China Mobile Beijing's office since 2013. "Apple and China Mobile can do a lot more things together," Cook pointed out. Xi added that instead of restricting them to the handset business, the two companies can look into opportunities presented by the burgeoning mobile Internet industry, which is giving birth to rapid-developing technologies and various new business fields. However, they did not disclose further details.