| Abstract
| - 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 ( $z=4.763$, $\rm I=17.3$, $R=19.1$) 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 $\rm 1.0\pm 0.4\times 10^{-3} ~sq\ deg^{-1}$ for flat-spectrum $z>4$ QSOs with $S\ge 72$ mJy and $\it R < 21$ mag.
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