March 27 (Reuters) - British construction company Kier Group Plc said it was considering making an offer for infrastructure maintenance provider May Gurney, setting the stage for a possible bidding war with smaller peer Costain Group Plc.
Costain, which builds and maintains highways, rail stations and airports, said on Tuesday it had agreed to merge with May Gurney in a deal that would create a company with annual revenue of 1.6 billion pounds ($2.42 billion).
Shares in May Gurney Integrated Services Plc, which maintains highways, rail and utilities services, were up 30 percent at 239 pence on the London Stock Exchange at 1408 GMT.
Kier said on Wednesday it had made previous attempts to discuss a potential combination with May Gurney and had been monitoring the company's recent performance.
The construction business of Kier offers engineering and contracting services for infrastructure and building projects, while its property business builds houses and invests in office, industrial and retail properties.
Kier's shares were down 3 percent at 1,138 pence, while Costain shares were down 5 percent at 289 pence.