China's smartphone market contracted in the first quarter for the first time in six years with Apple becoming the top vendor, researchers said Monday.

International Data Corporation (IDC) said figures from its mobile phone tracker show that 98.8 million smartphones were sold in China in January-March, down 4.3 percent from the same period last year.

"This is the first time in six years that the China smartphone market declined year-on-year as the market continues to mature," IDC said in a statement.

Compared with the previous quarter, the market shrank 8.0 percent "on the back of a large inventory buildup at the end of last year", it said.

Apple was the top vendor in China during the quarter, selling 14.5 million units, up more than 62 percent from last year. It had a 14.7 percent market share.

Apple's rise from fourth place in the first quarter of 2014 was driven by strong consumer preference for the bigger screen of the iPhone 6 and the iPhone 6 Plus, IDC added.

The US phone maker was followed by Chinese brand Xiaomi with a 13.7 market share. Another Chinese firm Huawei was in third place with 11.4 percent.

South Korean technology giant Samsung, which held the top spot in the first quarter of 2014, fell to fourth place.

Sales of Samsung smartphones in China totalled 9.6 million units, down 53 percent from last year, with the firm's market share shrinking to 9.7 percent from 19.9 percent as consumer preferences changed.

"Smartphones are becoming increasingly saturated in China," said Kitty Fok, managing director at IDC China.

"China is oftentimes thought of as an emerging market but the reality is that the vast majority of phones sold in China today are smartphones, similar to other mature markets like the US, UK, Australia and Japan," Fok said.

"Just like these markets, convincing existing users as well as feature phone users to upgrade to new smartphones will now be the key to future growth in the China market."