(Reuters) - Smartphone shipments for Apple ( AAPL ) and Samsung declined in the fourth quarter globally, as they grapple with intense competition from Chinese companies including Xiaomi ( XIACF ), according to preliminary data from the International Data Corporation (IDC) on Monday.

The global smartphone market rebounded strongly after two years of decline, with Chinese smartphone companies rapidly expanding their market share through aggressive growth in low-end devices and a strong focus on the domestic market.

"While we remain optimistic about continued growth in 2025, the threat of new and increased tariffs from the new US administration has elevated uncertainty across the industry," said Nabila Popal, senior research director for worldwide client devices at IDC.

Apple's ( AAPL ) global shipments fell by 4.1% to 76.9 million units in the fourth quarter, while Samsung's shipments dropped by 2.7% to 51.7 million units, as competition from Chinese companies such as Xiaomi ( XIACF ), Oppo, and Honor intensified, IDC reported.

In 2024, the iPhone-maker topped the global smartphone market with 18.7% share followed by Samsung at 18% and China's Xiaomi ( XIACF ) at 13.6%.

However, among the top five smartphone brands last year, Apple's ( AAPL ) shipments fell by 0.9% and Samsung's by 1.4%, while Xiaomi ( XIACF ) showed the fastest growth with a 15.4% increase in shipments.

Chinese mobile makers shipped 56% of the global smartphones in the fourth quarter, marking the highest combined volume ever in a quarter, as they expanded their footprint across Europe and Africa, boosted by their low-end and mid-range devices.

"Despite the continued growth across several regions, we have seen a decreased demand for foldables in the market, despite intensified promotions and marketing," said Anthony Scarsella, research director for client devices, IDC.

Smartphone makers have started shifting research & design spend away from foldable smartphones as consumer interest remains flat, Scarsella said.