Sources close to the firm said the group's QS and project management arm, Citex Project Services, would be subject to a management buyout in the "next few weeks".
This could mean a dramatic return to the sector for Bucknall, who was chairman of listed QS Bucknall Austin until it underwent a management buyout, delisted and changed its name to Citex in 1998.
Market sources said Bucknall was likely to take up a non-executive role and put some cash into the venture if the deal went ahead.
Rumours have abounded in the sector over the past months that Bucknall, the founding partner of Bucknall Austin, would be making a return to Citex.
The firm formed from a buyout could be renamed Bucknall Austin.
After leaving the listed QS in 1998, Bucknall took up a post as managing director of Jarvis airport services, as well as entering the IT and energy sectors.
One source close to Citex said Bucknall's return would be a boost for the firm. He said: "It's great news. Now that Citex is what it is, a project manager and QS, that's what he knows and understands. He's in his 60s but he still is full of energy – he still runs marathons. He's an incredibly charismatic guy and he will do all he can to make it a success."
One source said a deal to take over the £20m-turnover business was imminent. The source said: "A buyout is the preferred route. The deal is at a delicate stage but it's quite close."
Citex Project Services was the last third of the Citex Group to be disposed of; deals for the other two-thirds were struck last summer.
The firm's facilities management division was sold to Carillion for £11.5m, and its Asian division sold to EC Harris. Both deals were concluded last August.
The deals left Citex Project Services as a private firm owned by Citex shareholders, which include Phoenix Equity Partners and Legal & General Ventures.
After the two sales, chief executive Oliver Jones said talks had been held with potential suitors for Citex Project Services but there were no plans for an immediate deal.
The QS business is run by managing director Ann Bentley.