INDONESIAN RUPIAH SLIPS AGAINST MARK AND YEN The Indonesian rupiah has held steady since its 31 pct devaluation against the dollar six months ago, but has slipped against the mark and to a lesser extent against the yen, according to central bank figures. In the past month, the rupiah has fallen five pct against the yen. Today's middle rate per 100 yen was 1,129.78 against 1,075.20 at end-February and 1,058.6 at devaluation in September. Bank Indonesia's quoted rate for the dollar, the main currency for Indonesia's oil and gas exports, was 1,644.0 today, the same rate fixed at the time of devaluation. The rate for the West German mark was 913.28 today, a sharp drop from September when it was 786.06. The British pound has risen to 2,657.93 against 2,429.83. The value of the rupiah is set daily against a basket of currencies by the central bank. The rise in the value of the mark and the yen has hit Indonesia by increasing its debt servicing levels. Its total disbursed foreign debt is estimated by the World Bank at 37 billion dlrs. Japan is one of Indonesia's key trading partners, taking half its oil exports.