(Corrects billion won to trillion won in first paragraph)
SEOUL, April 17 South Korea said on Wednesday it would buy attack helicopters worth 1.8 trillion won ($1.6 billion) from Boeing Co. to improve its ability to respond to threats from North Korea.
The decision to buy the new helicopters was initiated before tension between North and South Korea rose sharply after North Korea's third nuclear test in February.
Boeing's AH-64E Apache Guardian helicopters beat the AH-1Z Viper built by Bell Helicopter, a unit of Textron Inc, and the T-129 of Turkish Aerospace Industries, an official at the Korea Defence Acquisition Programme Administration said.
"Apache's engine capability and weapons load, as well as the improved capability of target acquisition were given higher ratings," the official told reporters.
The officials at the briefing declined to say how many helicopters were involved, but one official told Reuters the deal was for 36 aircraft.
South Korea is also seeking 60 fighter jets this year.
For that deal, the Lockheed Martin Corp F-35 stealth fighter and Boeing's F-15 Silent Eagle fighter are in competition with the Eurofighter Typhoon, developed by a consortium of EADS, Finmeccanica SpA and BAE Systems.
($1 = 1115.0750 Korean won) (Reporting by Jack Kim and Ju-min Park; Editing by Robert Birsel and Miral Fahmy)