Developer plans to work with Carillion, Kier and HBG on a design-and-build basis if project gets go-ahead.
The construction of the £2bn project, which was expected to gain planning permission from Camden council at a two-day committee meeting this week, could start as soon as next summer.
Tony Giddings, Argent's development director, described the contractors as "companies we have worked with before and those we are building a relationship with" for the project's first phase.
He said: "We don't want to construction manage this and become an organisation of 800 people, so we're going to work on a design-and-build basis."
The first phase, which consists of two speculative office buildings at the southern end of the site, could start by mid-2007. Housing will also be included early on in the scheme, as required by Argent's section 106 agreement.
Phase two, at the northern end of the site, will accommodate St Martin's art college in the 54,000 m2 Granary Complex, which is occupied by cultural and leisure facilities.
Giddings added that Argent would aim to have many of the construction elements prefabricated, such as toilet pods, air-conditioning ducting and fan-core units.
However, he stressed he wanted "to give strong character to the buildings, to give interest to the site. That's why we have worked with so many signature architects. But prefabrication saves a lot of time and snagging".
As Building went to press, approval was expected to be granted at a planning committee on Thursday evening. Camden council last month recommended full approval for the 67-acre scheme, saying that it offered a "genuinely mixed-use development" and a "very high standard of design".