Chinese infrastructure company ZTE posted a 48 percent increase in profits due to lucrative contracts to construct China’s 3G networks.

ZTE made $359.7 million on $8.82 billion in sales in 2009, $4.49 billion of which were attributed to contracts in China. The company’s domestic sales rose 74 percent, helping to make it China’s largest supplier of 3G network equipment.

Sales growth was slower in ZTE’s international operations, which grew 11 percent to $4.37 billion. ZTE said the impact of the global financial crisis and “lackluster” international telecom market were partially offset by its cost-competitiveness and technology.

The company remained optimistic about its growth in Europe and the United States, saying its carrying, access and service networks were “gaining footholds” in those regions. ZTE said Europe and the United States are “set to become significant growth spots” for it in the coming years.

ZTE recently ousted its long-time President and CEO Yin Yimin in favor of Shi Lirong, an executive vice president who joined the company in 2004. Lirong’s appointment came amid rumors that Yimin would resign over ZTE’s struggle to compete with rival infrastructure company Huawei, which is also based in China.

Huawei has landed high-profile contracts in several key markets, including deals with Clearwire and Canada’s Sasktel. Huawei made $2.68 billion on $21.8 billion in sales last year.