BEIJING, March 26 (Xinhua) -- Authorities in Beijing tightened regulations on commercial real estate projects, aiming to strip them of housing functions and cool down the city's overheated housing market.

According to an official statement released late Sunday night by the city's housing, urban planning, industry and commerce, and banking authorities, new commercial projects shall only be sold to qualified enterprises, public institutions and social organizations, and the smallest unit for sale should not be less than 500 square meters.

Second-hand commercial housing can be sold to individuals who have paid income tax or social insurance for five consecutive years and have no houses under their names in Beijing, the statement said.

In the meantime, personal loans for purchasing commercial real estate have also been suspended.

Real estate agencies that mislead individual home buyers by falsely advertising housing function of commercial projects will be severely punished.

Due to Beijing's high prices of residential buildings and strict housing purchase rules, home buyers turned their eyes to small-unit commercial projects for transitional housing and investment.

Beijing has introduced a slew of policies over the past two weeks to rein in the surging housing price, including raising the down payment for second homes, imposing stricter tax regulations on residents without a local hukou (household registration), and shutting down real estate agencies for illegal operations.