Australian shares closed flat on Thursday, an improvement of sorts after five straight losses, after continuing investor caution over a British exit from the European Union wiped out the gains from a promising morning rally.

The benchmark S&P/ASX200 index was up nearly 1 per cent in the first hour of trade but by the close had drifted to close marginally lower at 5146.0, down 0.02 per cent on the day. The broader All Ordinaries inched up by a similarly small margin to 5231.7.