Mr Soper confirmed yesterday that while he was still doing some work for the trust, his fixed term contract ended in March, and his role had mainly been to get the project through "a quite intense workload", of financial and administration work.
Mr Soper was appointed chief executive in September last year, when former chief executive Darren Burden became development director.
The role of stadium operator and event manager, which the job would become, was the sort of work "I haven't done".
Trust chairman Malcolm Farry said the trust would be advertising internationally from next Saturday to fill the position.
"This was always planned. Mr Soper was employed to get financial reporting systems and a financial overview in place, but "had no interest in going any further than that".
"Ewan had always indicated his interest was only through to the part where construction would start," he said.
"We discussed an extension of time, but he wanted to stick to his original decision."
The role of the new chief executive had a position description Mr Farry said ran to nine pages.
It would continue to involve fundraising, and expand to sales and marketing so the business could be operating once the stadium was built.
"The CEO will look after all those areas. It will be a big job, but a very exciting job.
"To have this project through to opening and beyond is a good thing to have on your CV."
One aspect still to be finalised was how the chief executive's role would fit with the new council-controlled company, tentatively called Otago Venues Ltd, that will be set up to own and operate the stadium.
Employment agency Sheffield, the company the Otago Rugby Football Union used to find its chief executive in 2007, had won a contract to find the trust's new chief executive.
Mr Soper said he was looking for a new job, though with the current economic climate, it was not the best time to do so.
