We observed 5'x5' stellar fields around 31 (radio-loud) ICRF quasars in the J, H, Ks bands with the NTT/SOFI. All target sources were detected in the 3 bands with magnitudes in the range 13-18. Preliminary astrometric reductions have been performed with the UCAC1 as reference catalogue. Relative quasar positioning, from one band to the other, appears to be better than 10 milli-arcseconds (mas). Departures between the radio and optical/IR positions up to 100 mas are observed, and may reflect local biases of the optical reference frame.
SF2A-2003: Semaine de l'Astrophysique Francaise
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