Rental demand for Grade-A offices in Guangzhou, the capital of Guangdong province, remained strong in the second quarter of the year, with the vacancy rate reaching the lowest level since 2011, according to an industrial report.

In the city's booming Zhejiang New Town, a new business area, the vacancy rate of Grade-A offices declined to 20.5 percent, according to the a report released by global property service provider Colliers International.

"A growing number of financial organizations have expanded their business in the Pearl River Delta, showing greater interests in rents of Grade-A offices," said Liang Jie, associate director of office services tenant representation with the Colliers International (Guangzhou).

Rental price of Grade-A offices increased 2.2 percent year-on-year to 154.7 yuan per square meter in the second quarter of the year, according to the report.

The price will decline steadily in the near future as four more new Grade-A office buildings, with an area about 450,000 sq m, will open services in the second half of the year, according to Liang.