The manager of Hong Kong- listed Spring Real Estate Investment Trust says the premium quality of its property portfolio and diversified tenant mix are its competitive advantages. These allow it to outperform its competitors on the mainland, including Hui Xian Reit - an affiliate of Li Ka-shing's Cheung Kong - said Toshihiro Toyoshima, chairman of Spring Asset Management, which manages Spring Reit. "Beijing Oriental Plaza was in a great location probably 10 years ago," said Toshihiro Toyoshima. But by current standards, the office buildings are not "premium grade", he said. Beijing Oriental Plaza, a key asset of Hui Xian, is located in Wangfujing district, a tourist area rather than a core commercial district, Toyoshima told the South China Morning Post . Developed on a plot of land with a total area of about 100,000 square metres, Beijing Oriental Plaza has a total gross floor area of about 800,000 square metres. Toyoshima said when Beijing Oriental Plaza was built, it was subject to building height restrictions. As a result, its floor to ceiling height was about 2.5 metres, lower than the 2.7 metres offered by Spring Reit's China Central Place. Hui Xian was unavailable for comment. Spring Reit, which is owned by AD Capital, an investment firm based in Japan, was listed in Hong Kong in December last year. The trust owns two office towers in China Central Place, in Chaoyang district - part of Beijing's central business district - with a gross floor area of 120,245 square metres, plus 600 car parking spaces. China Central Plaza is a mixed-use commercial property comprising offices, a hotel, residential space and a popular shopping mall, Shin Kong Place. The office towers are classified as "premium grade" office buildings, based on factors such as their location and tenant profile, among a total of 13 "premium grade" office buildings in Beijing, according to property consultancy DTZ. Major tenants include Deutsche Bank, software giant SAP, magazine publisher Conde Nast, Zhong De Securities and Global Law Office. Toyoshima said Spring Reit expected positive growth in revenue driven by positive rental reversion - where rents are increased when leases end - over the next few years. New supply is limited, as there are only three grade-A office buildings to be completed by 2016, with total space of 200,000 square metres, accounting for only 8.6 per cent of the total stock of 2.61 million square metres at the end of last year, DTZ said. Toyoshima said top grade or premium grade office spaces in Beijing have higher growth potential than other office buildings. He said Spring Reit, which has only one project in its portfolio, is looking for expansion without harming the dividend payout.