May, 48, will replace Paul Whitmore, who has decided to step down after 26 years with Laing 鈥渢o pursue other challenges鈥�. He was chief executive for only 14 months.
The news came as a shock to Mowlem, which responded quickly by promoting director of performance Steve Bowcott, 44, to managing director.
A Mowlem spokesperson said staff were informed of the news last Thursday. May left immediately and is now on 鈥済ardening leave鈥�.
May was formerly chairman of Mowlem鈥檚 northern division and managing director of its domestic repair business, Skillbase.
A number of industry and City players have commented that Laing鈥檚 senior positions are filled by accountants and quantity surveyors, rather than by people with direct construction experience. May, who is a civil engineer by profession, will change the balance.
Laing Construction鈥檚 chairman Jim Armstrong said it was 鈥渋mportant鈥� that Laing kept its position in the civil engineering market but said that that was not the only reason for appointing May.
He said Whitmore had written to him early in the new year saying he wanted to step down and that he had immediately appointed headhunters to find a replacement.
Armstrong added that the move would have no impact on the implementation of Laing鈥檚 business plan, which was drawn up after a review by KPMG last year and resulted in 800-plus job losses.
Whitmore will stay on at Laing until the end of the month but his plans after that are unknown.
May鈥檚 departure comes at a bad time for Mowlem, which announced its year-end results yesterday.
May鈥檚 replacement, Bowcott, was appointed late last year to oversee the changes recommended in a strategic review by McKinsey. Before that, he was chairman of Mowlem鈥檚 South-west division for 10 years.
