JAKARTA (REUTERS) - Indonesia's central bank governor pressed exporters on Friday to sell their dollars to help the weakened rupiah, repeating assurances that Bank Indonesia would be in the market to maintain stability.

The rupiah slipped below 12,000 to the dollar on Thursday to a five-year low. It has since recovered some ground but a Reuters poll of currency analysts showed bearish bets on the rupiah had risen to their highest since August "The demand for dollars is quite big to meet year-end demand ... the pressures is temporary ... (and is) due to preparation ahead of 2014. We have to stay vigilant and not panic to overcome this," Governor Agus Martowardojo told reporters.

"The supply of dollars is there but not as much as we expected. We urge exporters and forex holders to sell their dollars for a balanced supply-demand in market," he said.

He added: "In general, we be in the market to maintain stability." The rupiah is Asia's worst performing currency so far this year, having lost more than 19 per cent of its value against the US dollar.