Rent for Beijing's top offices has dropped by 0.7 percent year-on-year in the second quarter and is expected to continue to slide as more office buildings are put on the market, real estate consultancy company Savills predicts.

With at least three new office buildings entering the market in the second quarter, Beijing's Grade A office space has increased to 102 million square meter.

The vacancy rate also rose to 6.6 percent, 0.5 percent up on the first quarter.

Cushman &Wakefield, another commercial real estate services, put the vacancy figure even higher at 7.2 percent.

Savills' report stated that the average rent in Beijing Grade A office market is 338 yuan ($49.70) per square meter per month, after decreasing for the last four quarters.

Savills predicted five more Grade A office projects would be launched in Beijing in the next half of year, adding 3.37 million square meters. The vacancy rate could rise to 8 percent, leading to a further slide in rent, the company predicted.

However, rent in the Zhongguancun area, Beijing's high-tech hub increased by 13.8 percent in second quarter on a year-on-year basis, as the country pushes the Made in China 2025 strategy, according to Cushman &Wakefield.

"Strong occupier demand from the industry, coupled with limited office availability, has caused rent levels there to be on the rise" Sabrina Wei, head of research at Cushman & Wakefield in north China, said.