Trimming its early gains, the rupee was up by 18 paise to 57 rupees 80 paise against the dollar on selling of the US currency by banks and exporters in view of its lower value in overseas market. The rupee resumed higher at 57 rupees 75 paise per dollar as against the last closing level of 57 rupees 98 paise at the Interbank Foreign Exchange market. It moved up further to 57 rupees 63 paise on selling of the US currency. However, it failed to maintain its initial gains and was quoted at 57 rupees, 80 paise per dollar a shortwhile ago on mild dollar demand.