From: AFM European Air Power Survey, August 2001.
Re : Slovenian PC-9's
"Part of the fixed wing squadron is a combat air unit, with nine upgraded PC-9M Swifts, which now have been declared combat ready. A Slovenian engineering team, working with the French firm Alkan, Israel's El-Op/Radom and Belgium's FN Herstal, has developed a system which enables the PC-9 to use a variety of modern weapons. In combat configuration, the upgraded PC-9M Swift is capable of carrying up to 2,292lb (1,040kg) of armament on six under-wing pylons".
(Unfortunetly, the article doesn't give specific weapon details).
Hope this helps.
Silver.