The rupee continued to rule firm against the American currency for the fourth day, moving up by another 20 paise to close at a fresh three-week high of 66.77 on sustained selling of dollars by banks and exporters amid strong recovery in domestic equities. Expectations of more foreign capital inflows in view of robust domestic equities boosted the rupee, a forex dealer said. The rupee has gained 68 paise or 1.01 per cent in four days.