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We present results of a new, large survey for high-redshift radio-loudquasars, which targets quasars with z>4. The survey is based on the PMN andNVSS radio surveys, optically identified using digitised UKST B, R and Iplates. Six new z>4 flat-spectrum QSOs have been discovered, and one previouslyknown z>4 QSO rediscovered, based on their red optical colours. The QSOsdiscovered in this survey are bright in both radio and optical bands; inparticular PMN J1451-1512 (z=4.763, I=17.3, R=19.1) and PMN J0324-2918(z=4.630, R=18.7) are very luminous. PMN J1451-1512 at z=4.763 is also now themost distant radio-selected quasar. In addition, 9 new quasars with 3.5<z<4.0were discovered during the survey. We present spectra and finding charts forthe new quasars. We also derive a surface density of 1.0+/-0.4 x 10^-3 /sq degfor flat-spectrum z>4 QSOs with S>= 72mJy and R< 21mag.

Discovery of radio-loud quasars with redshifts above 4 from the PMN sample