Beijing's Central Business District will double in size over the next eight years in a bold new plan that may involve the relocation of 10,000 households in one of city's most densely populated residential areas.

According to the proposed government plan released Saturday, a 3-sq km expansion, from the East Third Ring Road near Guomao to the Fourth Ring Road near Sihui Bridge, will be completed in the next six to eight years.

It will attract more major multinational corporations and create as many as 100,000 new jobs.

Although the cost for the project is unknown, the Chaoyang district government, which is overseeing the expansion, is keen to turn more residential areas into commercially successful headquarters for some of the world's largest multinational corporations.

"About 85 percent of the current CBD area has been taken by companies," said Wu Guiying, executive vice-governor of the Chaoyang district and director of the CBD administrative committee.

"The area is eager for more capacity to hold more business opportunities," she said, ahead of a seminar on Beijing's CBD expansion, which begins today.

The world's leading architects have completed seven preliminary CBD expansion designs including SOM Architect and KFP Architect from the US, and ADPi Company from France. The plans will be displayed to the public during a six-day CBD International Business Festival.

Senior officials, business people and analysts are also invited to give advice on how the CBD should expand.

Yesterday, the housing market was the first to react to proposed CBD mega-development.

Developers and real estate dealers near the CBD in east downtown Beijing told METRO said the prices for both new and second-hand apartments have soared since early this year rising to 20,000 yuan ($2,930) per sq m.

"Before the news came out that the government will expand CBD, the prices were more reasonable between 12,000- and 13,000-yuan per unit," said Wang Mei, a property broker.

"Now every apartment has grown by one third," she said, pointing to the nearly finished residential premises near her office at Sihui Bridge, the east end of the planned expansion.

Li Xin, a developer for a luxurious CBD residential compound set to open by the end of this month, said all the 987 apartments in his compound were sold out despite the high prices for at least 21,000 yuan per unit.

Ma Ning, a Beijing resident who was looking at apartments at Li's CBD residence with his wife yesterday, was told no apartments were available.

"We were thinking of selecting a place for our son who works in a company nearby," he told METRO.

"The price seems high, but we just want him to have a good place to work and live."

The current CBD area near Guomao area has nested more than 15,000 firms and financial institutions.

Last year, the city government has attracted $1 billion in foreign investment, taking up half of the tax revenues for the Chaoyang district government.