UK defense group Cobham spent GBP21.1million on a Danish spy gadget company yesterday in its bid to become market leader in counter-terrorism products.
Spectronic, based in Grenaa, specializes in audio surveillance and internet interception products, and employs 60 people.
The acquisition is the fourth such purchase by Cobham, based in Dorset, for its Chelton avionics division.
All four firms manufacture secret technology sold only to governments.
The anti-terror industry has been booming since the terrorist attacks on the World Trade Centre in 2001.
Spectronic's products include technology which enables governments to listen to mobile phone conversations.
Cobham said the cash purchase of Spectronic was "highly complementary" to other firms it has acquired.
In April, Cobham spent GBP26.3million on DTC Communications, a US maker of surveillance and tracking products.
These include communication systems which link field personnel to unmanned aerial and ground vehicles.
DTC has 150 employees, including a technical staff of 41, and is based in Nashua, New Hampshire.
Cobham also owns Canadian firm Orion Electronics, which is based in Nova Scotia and makes GPS tracking equipment largely for US forces.
Another subsidiary is Micromill Electronics, a Hampshire company that makes radio data systems which are designed to operate in harsh conditions for the Ministry of Defense.
A Cobham spokesman said: "The single thread that runs through all of these firms is counter-terrorism.
"The homeland security market is growing as we all know and these acquisitions reflect that.
"What Cobham is trying to do is be in market-leading positions in niche product areas." The firm added that it "wouldn't rule out further acquisitions."
Cobham chief executive Allan Cook said: "The acquisition of Spectronic provides our customers with a broader range of homeland security communication solutions.
"Of special interest are their intercept products for internet applications, a rapidly growing market." Cobham posted a 7.8 per cent rise in first-half pre-tax profits to GBP51.8million in September, and hinted that the second half could be even better.