Second-tier cities see oversupply of office space

China's second-tier cities have an oversupply of offices, with companies halting expansion amid a slowdown in the world's second-biggest economy, according to one of the country's biggest commercial builders.

"There are a lot of empty buildings," Zhang Xin, chief executive officer of Soho China Ltd, said in an interview with Bloomberg Television on Wednesday.

"Concentrating on cities such as Beijing and Shanghai is less risky, but when we go to second- and third-tier cities, demand instantly declines."Soho China is the biggest developer in Beijing's central business district, where office rents fell in the second quarter, the first decline in almost four years, according to property broker Knight Frank LLP.