Chinese smartphone brands Oppo and Huawei are tightening their grip on the world's biggest market, grabbing local share and squeezing out Apple Inc and Samsung Electronics Co.

After including vivo Mobile Communication Technology Co, Chinese vendors held the top three slots and accounted for 48 percent of shipments in the country during 2016, research firm International Data Corp said.

With a lineup of flexible and curved-screen devices, they look set to dominate the market in 2017. A decline in Apple shipments in the fourth quarter highlighted how the iPhone 7 failed to make as big a splash in the face of escalating competition.