FTSE 250-listed construction, services and property group Kier Group has signalled its possible interest in acquiring AIM-listed May Gurney Integrated Services just hours after the latter and UK engineering company Costain published details of a proposed all-share merger.Kier Group said that it had noted the announcement regarding the proposed merger of May Gurney Integrated Services with Costain Group on Wednesday morning, adding that it holds May Gurney in high regard and views it as a "good quality support services business with a range of services which complements Kier's existing offering". The company added: "Kier believes that a combination of Kier and May Gurney would create significant value for shareholders, establishing a market-leading and well-balanced business." While it said that there could be no certainty than an offer would be made, the company said that it had been monitoring May Gurney's recent performance and would be "considering its options" in light of the recent announcement.Earlier on Wednesday, Costain issued a statement to the London Stock Exchange saying that the boards of Costain and May Gurney Integrated Services had reached agreement on the terms of a recommended all-share merger of Costain and May Gurney. Costain said that the merger would be conditional on the approval of both companies' shareholders.Kier Group's share price was down 3.48% to 1,138p at 14:10 on Wednesday.MF