Major US architect Skidmore, Owings & Merrill (SOM) has won a three-horse race to design the centre of Sri Lanka’s controversial, Chinese backed Port City of Colombo.

The competition was held to gather design concepts for the financial district and the marina area of the port, which Sri Lanka’s government had previously suspended amid concern over undue influence from China and irregularities in the contract process.

Now back on, the port is expected to have an initial investment demand of $1.5bn, rising to $15bn upon completion of all its phases.

The other two designers were Nikken Sekkei of Japan and San Francisco’s Gensler, presently the world’s largest architect.

The three designers were required to work within the existing masterplan and the investment value of the scheme.

The participants were given the freedom to reorganise land use, mix, height and other development parameters provided they kept to the allocated boundaries.

SOM’s entry was the unanimous choice of the competition’s international jury. It was particularly praised for “demonstrating exceptional sensitivity to the ecological and cultural context of Sri Lanka”.

The project will give Colombo a 269ha extension on land reclaimed from the sea. It is being developed by the government of Sri Lanka and Chinese group, CHEC Port City Colombo, a subsidiary of the China Communications Construction Company (CCCC).

The ambitious scheme, part of China’s “One Belt, One Road” global transport infrastructure strategy, is set for completion in 2041.

Altogether, the city will have five distinct districts: the Financial District, Central Park Living, Island Living, The Marina and the International Island.

N Rupasinghe, the secretary to the Ministry of Megapolis and Western Development, commented in a press statement that the project was intended to present a modern image of Sri Lanka. He said: “Unlike anytime in the history of our country where our cities have taken centuries to grow organically, today we have a planned city which will be completed in 25 years.”

Lim Kian Siew, Director of Planning and Development at CHEC Port City Colombo, added that the company would take the best ideas from all three of the submissions. He said: “All the submissions contained ideas we consider worth exploring. We are open to ideas from all the entries provided they are viable and implementable.

“Of course every competition needs a winner and SOM has proved to be better than the others.”

SOM said its design was influenced by Sri Lanka’s varied landscape and complex tropical climate.

It said: “The squares, canal edges, gardens, a new harbour, and a new city park take cues from the local environment to create a sympathetic proposal that is rooted in the country’s unique geography and ecology.”

The port city has been an object of intense political controversy both within Sri Lanka, and as an element in the growing geopolitical rivalry between India and China. See related stories below for more on this aspect of the scheme.