Oil prices continued to extended gains in Asian trade as the dollar remained weak against major currencies even as economic prospects in USA improved. Light sweet crude for June delivery traded at US$108.8, while Brent crude stood at US$121.3. The Dollar Index that measures the dollar vs six major currencies, dipped for a second day to 74.88, falling by 5.3% since the start of the year. As the dollar weakens, it makes commodities priced in the US currency more attractive for investors. This week saw release of better-than-estimates home construction figures and company earnings in USA that indicated signs of an improving economic outlook, and stoked speculation that fuel demand may increase.