Sources said the deal could be announced as early as today. "The deal is close, no doubt about that, and they are finalising the details," said one analyst. "But it's never completely certain until they announce it."
The deal would allow Wimpey to overtake Persimmon and regain its position as the UK's largest housebuilder.
Bill Forrester, Laing's executive chairman, has gone for Wimpey's bid because he is keen to tie up the deal quickly. However, the selling price is £100m lower than Laing's original asking price, which is likely to disappoint investors.
Laing plans to use the money to fund its PFI business.
Wimpey has driven a hard bargain because it was criticised for paying too much for McAlpine Homes
The housing arm's assets are valued at about £250m, which means Wimpey will not be paying a premium on them, as it did last year when it bought Alfred McAlpine Homes for £460m.
"Wimpey has driven a hard bargain with this one because [chief executive] Peter Johnson was criticised last year for paying too much for McAlpine Homes," said an analyst. "Wimpey should have been able to offer more than the management buyout because of the cost savings it could get out of the business, but it hasn't."
The declining value of shares on the stock market and concerns about the housing market played a part in keeping the price down.
Lidgate's buyout first hit problems in the summer, when venture capitalist 3i became unsure whether to back it.