BEIJING, Jan 5 (Reuters) - China's central bank pledged on Friday to keep the yuan exchange rate stable, further optimise credit structures, strengthen international monetary cooperation and promote the development of the offshore yuan market.

"Prudent monetary policy needs to be flexible, appropriate, precise and effective," the central bank said in a statement outlining numerous measures to invigorate the economy.

The bank also said it would use a variety of monetary policy tools to maintain reasonable and sufficient liquidity and keep liquidity reasonably ample. (Reporting by Beijing newsroom; Writing by Bernard Orr; Editing)