Koolhaas' practice, OMA, with Arup, is understood to have been selected from a shortlist including Toyo Ito and the Shanghai Institute of Architects. An announcement confirming Koolhaas' selection will be made in the next two weeks.
The project, for state-controlled television station China Central Television, will cover 560,000 m2 of space, including a public performance centre. It will also include a 230 m broadcasting tower.
China requires new facilities to televise the Olympics and the government is spending nearly £24bn on hosting the games, including developments such as 140 km of railway lines, 300 km of roads and an Olympic village.
A source close to the television headquarters project said it will be a key element in the central business district, which has been under construction for the past decade. The source added: "The district is being built to ensure that Beijing can compete with Hong Kong and Tokyo."
Another source noted that it was deemed a priority project because Beijing was concerned that Shanghai had in effect become China's capital city after developing its own financial quarter.
The business district is being built to compete with Hong Kong
Beijing's business district is located to the east of the Forbidden City and includes plans for a 330 m2, 70-storey China World Trade Centre 2, which will be the area's tallest building.
The state-funded business district was set up in the early 1990s and its development has been accelerated by the introduction of a five-year plan for 2001-05.
The business district covers a 4000 m2 area and includes 500 buildings. The average height of these buildings is expected to be well over 100 m.
The plans have attracted major companies to the region. South Korea conglomerate LG Group is building two 30-storey towers near Tiananmen Square to house its expanding China operations.