TCC Group chairman Charoen Sirivadhanabhakdi, joined by his wife, Khunying Wanna, and son Panote, announces the One Bangkok project, the largest property investment at one site in Thailand. PORNPROM SATRABHAYA

TCC Group, owned by billionaire Charoen Sirivadhanabhakdi, has announced a 120-billion-baht investment to develop One Bangkok, marking the largest-ever property investment in a single site in Thailand.

The gigantic mixed-use project is planned for the site of the former Suan Lum Night Bazaar on Rama IV Road.

The group has also snapped up other prime locations along the busy street, running from Sam Yan to Khlong Toey, for property projects totalling 14 billion baht.

The One Bangkok project is expected to heat up property along Rama IV and Wireless roads, as a mixed-use development recently announced by Dusit Group along with CPN Plc is expected to have an investment cost of 36 billion baht.

Panote Sirivadhanabhakdi, group chief executive of Singapore-based property firm Frasers Centrepoint Ltd (FCL), said One Bangkok Holdings Co has been set up to develop the project with registered capital of 3 million baht, set to rise to 35.8 billion to foster the huge development project.

The holding company is a joint venture between TCC Assets Thailand Co, holding 80.1%, and Frasers Property Holdings Thailand Co, which holds 19.9%. TCC Assets is a subsidiary of TCC Group, while Frasers Property Holdings is a wholly owned subsidiary of FCL, which is also owned by Mr Charoen, chairman of both TCC Group and FCL.

"This project will be TCC Group's largest investment, where senior executive teams of FCL from 26 countries will join the development," said Mr Panote, the youngest son of Mr Charoen.

"It will transform the location and become a key centre on Rama IV Road."

The country's previous high for a property investment on a single site was 50 billion baht for Iconsiam, a mixed-use project by the Chao Phraya River scheduled to launch by the end of 2017.

Iconsiam is a co-investment of three partners: Siam Piwat, operator of Siam Paragon; Charoen Pokphand Group; and Magnolia Quality Development Corporation, a residential developer owned by the Chearavanont family.

One Bangkok will be located on a 104-rai plot on the corner of Wireless and Rama IV roads, close to the Lumpini subway station and opposite Lumpini Park. The plot was formerly used by Suan Lum Night Bazaar and the Pre-Cadet School.

Owned by the Crown Property Bureau (CPB), the plot is leased with a 30-plus-30-year contract to a consortium of TCC Assets and Univentures Plc, an SET-listed firm in which the Sirivadhanabhakdi family is a major shareholder, which won the bid in 2014.

"We get a grace period of nine years after winning the bid," Mr Panote said. He did not disclose a lease contract price.

"Despite the economic slowdown, we plan to press forward with all facets of the project," he said.

Su Lin Soon, chief executive of development for TCC Assets, said One Bangkok will have a total gross floor area of 1.83 million square metres, the country's largest construction area for one project.

With an open space and green area of 50 rai, the project will comprise five Grade A office towers with a total lettable area of 500,000 sq m, five luxury hotels with a combined 1,000 rooms, and three 30-storey luxury residential towers with retail space.

The company envisions the highlight as one super-tall office tower, with a height of over 380m and 90 floors -- a new landmark for the city. The tower will have office and retail space, a boutique hotel and an observation desk, Ms Soon said.

"The height is not as meaningful as the integration," Mr Panote said. The first phase is scheduled to open in 2021, with the full project due by 2025.

"We have never done anything to cannibalise each other," he said. "Every project should complement the others. This is a strength of TCC Group."

The other projects TCC Group is developing on Rama IV Road include Samyan Mitrtown, a mixed-use project with an investment of 8.5 billion baht being developed by SET-listed Golden Land Property Development Plc, in which the Sirivadhanabhakdi family holds a major share.

With a total gross floor area of 222,000 sq m, the project is located on a nearly 14-rai plot in the Sam Yan area on the corner of Rama IV and Phaya Thai roads, owned by Chulalongkorn University.

It is scheduled for completion by 2020 near Sam Yan subway station, about two kilometres away from One Bangkok.

Some 1.6 km southeast from One Bangkok along Rama IV Road, TCC Group has the rights to develop a 35-rai plot near the Khlong Toey intersection, also owned by the CPB. It is used as rental car parking for Queen Sirikit National Convention Center.

N.C.C. Management and Development Co, a TCC Group subsidiary, plans to invest 6 billion baht to renovate and develop an additional construction area of 180,000 sq m at the convention centre.

Opposite the centre, the 5-billion-baht FYI Center is an office building also developed by Golden Land.