Foreign exchange reserves declined by $100.7 million to $12,939.9 million in the week ending on July 15, 2006 the State Bank of Pakistan (SBP) said on Thursday. Reserves held by the SBP declined to $10,610.5 million from $10,672.2 million a week earlier however, those held by commercial banks declined to $2,329.4 million from $2,368.4 million.