South Korea's air force plans to buy eight Indonesia Aerospace-built CN-235-220 maritime patrol aircraft, with Seoul offering Jakarta two refurbished diesel submarines in return. Officials from both countries have been discussing the proposal for several months, and the final details could be hammered out during joint committee meetings on defence and logistics and as South Korean defence minister Lee Sang Hee visits Indonesia later in July. "The discussions have been going on for some time and we believe that a contract could be signed before the end of 2008," says an official from South Korea's Defense Acquisition Program Administration (DAPA), the country's arms procurement and export agency. The deal, which is likely to be worth around $1 billion, will see South Korea sell two of its nine 1,300t German-built HDW 209-class diesel submarines and related technology. It will also help Indonesia, a sprawling archipelago, to build its first submarine repair dock and enable its navy to better patrol its waters. In return, South Korea will get eight CN-235-220s that will be used for surveillance and maritime patrol duties. The CN-235 was jointly developed by Spain's CASA and IAe in the 1980s, with both companies producing variants independently. The South Korean air force bought 12 CN-235-100s from CASA and eight -220s from IAe in the 1990s, and uses the type for troop transport, surveillance and maritime patrol. Close defence relations between the countries led to Indonesia ordering seven Korea Aerospace Industries KT-1 trainers in 2003, and another 12 in 2006. KAI is negotiating with Indonesia to sell a third batch of the aircraft, while an armed variant dubbed the KO-1 is also being considered by Jakarta for a light attack aircraft requirement.