China and Hong Kong signed a 200 billion yuan ($29 billion) swap agreement today as part of Beijing's measures to help the city though the economic crisis, the Chinese central bank said.

'It will strengthen the outside world's confidence in the financial stability of Hong Kong,' the People's Bank of China said in a statement about the three-year agreement.

China last month promised a currency swap agreement with Hong Kong as Chinese Premier Wen Jiabao vowed 'strong backup' for the city.