KARACHI (Reuters) - Foreign exchange reserves fell to $17.64 billion in the week ending Sept 17 from $17.79 billion of the previous week, the State Bank of Pakistan said on Thursday. Reserves those held by commercial banks rose to $3.52 billion from $3.45 billion, according to the State Bank of Pakistan. The decline in reserves is due to scheduled debt repayments, said Syed Wasimuddin, chief spokesman for the central bank. Foreign exchange reserves hit a record $18.31 billion in the week ending July 30 but have eased due to debt repayments. The reserves were boosted in June by inflows of $411 million, including a $191.9 million loan from the World Bank, and a loan of $196.8 million from the Asian Development Bank. Higher export proceeds and a record inflow of remittances have helped Pakistans forex reserves grow steadily.