Indonesia has chosen South Korea as preferred bidder for its jet trainer project, officials said Tuesday, despite a reported attempt by Seoul's spies to steal secrets from a visiting Jakarta delegation.

The country's sole aircraft maker Korea Aerospace Industries (KAI) announced it had won the status from Indonesia's defence ministry, although the two sides have yet to complete negotiations on price and other details.

A final deal, if sealed, would pave the way for the first export of South Korea's T-50 Golden Eagle supersonic trainer jet, defence ministry officials said.

"Today is meaningful as we became the sixth country to export a supersonic jet after the US, Russia, Britain, France and Sweden," KAI president Kim Hong-Kyung told reporters, anticipating a final deal.

He said the T-50 beat competitors from Italy, Russia and other advanced aircraft makers.

South Korea unveiled the T-50 in 2005 with technology provided by US aircraft maker Lockheed Martin. It hopes to export 16 T-50 jets worth about a total of $400 million to Indonesia, Yonhap news agency said.

Indonesia plans to replace its ageing Hawk Mk-53 trainer jets that are scheduled to be decommissioned this year.

South Korean officials say the T-50 can carry out light attack as well as training roles. The South's air force plans to start deploying a more heavily armed version.

South Korea's spy agency came in for criticism in February following reports that its agents tried to steal commercial secrets from the hotel room of a visiting Indonesian trade delegation.

Newspapers said three agents from the National Intelligence Service entered the room on February 16 in an attempt to steal information on possible Indonesian arms purchases.

The intruders reportedly fled after a delegate abruptly entered the room and saw them copying files from a laptop computer.

South Korea and Indonesia have maintained close defence cooperation.

In 2008 Seoul signed a $90 million deal with Jakarta to buy four transport planes for the coastguard. Last July Indonesia agreed to join a South Korean project to develop fighter jets.