Irish developer Tiger is due to launch its new proposals for the former Morrison Street goods yard next week – after its original plans that included a towering 17-storey luxury hotel were thrown out following a public inquiry.
InterContinental Hotel Group was among the firms that had agreed to move on to the site under the original proposals but pulled out after the landmark hotel was dropped.
There had been fears that other companies which wanted to move onto the original site would also scrap their plans.
But it is understood that both Travelodge and Tesco still want to move onto the former Morrison Street goods yard site.
Tiger said that work could begin as early as autumn next year if it gets planning consent, and it also confirmed today that it is turning its sights on developing more office space – with one office as tall as ten storeys.
A spokesman for Tiger said: "Tiger are hopeful that the development of the site will act as a catalyst to regenerate the commercial heart of the area."
The increase in office space means that it is now estimated that up to 3,500 jobs could be created – much more than the original estimate of 2,150.
Stewart Taylor, a director at property firm CB Richard Ellis, said there would be demand for a tall office building.
He said: "The more higher levels you have, the more interest you get. If you can create ten storeys, you are double almost any other office in Edinburgh.
It is understood that the council recently commissioned Colvin & Moggridge to look at the Haymarket site, and it recommended a maximum of ten storeys at the site.
Charles Guest, a partner at Ryden, said there would be a "black hole" of no office development in the next few years – meaning that getting offices completed by 2013 may catch the market at a good time.
He added that transport links will give any offices at Haymarket an advantage. He said: "If you look at Haymarket, it is a transport node and it will be developed further as a transport node with tram, train and bus.
"In 20 years' time if we get high-speed rail it will add to that. Sites around railway stations will be increasingly important."