Cobham Ltd has a $3.6 billion offer to buy Ultra Electronics in a bid that could draw surveys in Britain due to Cobham’s US ownership. Shares in London-listed Ultra, whose major customers include the British and US governments, rose to 34 per cent to record a high of 33.18 pounds.

Cobham, based in Dorset, England and founded in 1934, is recognised for its pioneering air-to-air refuelling technology. It was bought by private equity firm Advent International last year, possibly triggering national security concerns in Britain about a takeover of Ultra Electronics.

Purchasing Ultra would help Cobham tap the maritime defence market, where Ultra sells sensors, torpedo and radar systems, mainly to Western customers. The company also makes a range of defence communication equipment and forensics software. Cobham makes devices used in electronic warfare and missiles and prefers to offer undertakings to the British government regarding national security, Ultra said.