  We present results of a new, large survey for high-redshift radio-loud
quasars, which targets quasars with z>4. The survey is based on the PMN and
NVSS radio surveys, optically identified using digitised UKST B, R and I
plates. Six new z>4 flat-spectrum QSOs have been discovered, and one previously
known z>4 QSO rediscovered, based on their red optical colours. The QSOs
discovered in this survey are bright in both radio and optical bands; in
particular 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 the
most distant radio-selected quasar. In addition, 9 new quasars with 3.5<z<4.0
were discovered during the survey. We present spectra and finding charts for
the new quasars. We also derive a surface density of 1.0+/-0.4 x 10^-3 /sq deg
for flat-spectrum z>4 QSOs with S>= 72mJy and R< 21mag.
