QUEENSLAND'S optional preferential voting system will remain for the next state election, after a review found it couldn’t be blamed for the high level of informal voting at the last federal poll.

The Australian Electoral Commission raised concerns about the level of unintended informal voting in Queensland in the August 2010 federal election, and whether it was due to differences between the federal and state voting systems.

But the state review found there may be other factors at play, as there was also an increased number of blank ballot papers, Attorney-General Cameron Dick told state parliament on Wednesday.

The Australian Electoral Commission is conducting its own review of voting patterns in the 2010 election.