New York's main contract, West Texas Intermediate for August delivery, rose 12 cents to $95.06 a barrel and Brent North Sea crude for August gained 19 cents to $111.58.
"Basically yesterday the US markets were closed and crude oil prices are quite muted," said Ker Chung Yang, a Singapore-based analyst at Phillip Futures.
Oil prices yesterday were boosted by the progress of eurozone talks to save debt-ridden Greece.
On Saturday, finance ministers approved the next 12-billion-euro slice of a rescue worth 110 billion euros ($160 billion) provided by the European Union and International Monetary Fund.
Crude traders are waiting for upcoming data from the United States for leads, including a report by the American Petroleum Institute (API) on crude stocks in the world's biggest oil consumer, Ker told AFP.
The API report on US crude stockpiles is usually released a day before the Department of Energy's weekly petroleum reserves data.