SWISS engineering giant ABB has had an £860m bid for Chloride – which protects against power cuts at Heathrow’s Terminal Five – accepted.
An offer of 325p a share has been agreed.
Chloride, whose products protect companies against power shortages, rejected an offer for £723m in April from Emerson.
Chloride would be integrated into ABB's Discrete Automation and Motion division.
ABB is being advised by Credit Suisse.