Amec Foster Wheeler has agreed to a £2.2bn takeover by Wood Group in a deal that brings together two of the UK's largest energy services companies.
Wood Group hopes to cut £110m in costs out of the combined business, which will provide services to oil and gas, chemicals and mining sectors.
Shares in Amec soared by 18.3% to 579p in early trading after details of the deal were released.
Aberdeen-based Wood Group is offering 564p a share for its British rival.
Wood Group's shares also rose, up 6.8% to 804p.