Newcastle-headquartered international bus and rail giant Go-Ahead Group confirmed on Monday it has received two separate approaches regarding possible cash takeover offers that it “would be minded to recommend” “should a firm offer be made.

Go-Ahead shares rose about 15% to £13.94 to give the firm a stock market value of about £600 million.

The two bidders — Australia-based transport firm Kelsian Group Ltd and a consortium of Australia’s Kinetic Holding Company and Spain-based transport infrastructure management firm Globalvia Inversiones — have been given access for due diligence.

They have until July 11 to make an offer or walk away.

Go-Ahead, which runs more than 6,000 buses in England and Britain’s largest passenger rail contract, becomes the latest UK transport takeover target after Aberdeen-based FirstGroup and Perth-based Stagecoach.

In a stock exchange statement, Go-Ahead said: “The board of The Go-Ahead Group plc notes the recent movement in its share price and confirms that it has received separate unsolicited, conditional approaches regarding possible cash offers” from Kelsian Group Limited and a consortium consisting of Kinetic Holding Company Pty Ltd and Globalvia Inversiones S.A.U.

Go-Ahead added: “The board of Go-Ahead carefully evaluated the approaches from each of Kelsian and the consortium together with its financial adviser, Rothschild & Co.

“Following the response by the board of Go-Ahead to their respective approaches, Kelsian and the consortium each submitted a series of revised proposals.

“The most recent revised proposals received from each of Kelsian and the consortium are both at a level which, should a firm offer be made, the board of Go-Ahead would be minded to recommend such a firm offer to Go-Ahead shareholders, subject to the agreement of other customary terms and conditions.

“Accordingly, both parties have been given access to undertake confirmatory due diligence.

“A further announcement will be made if and when appropriate …”