Benchmark oil for June delivery rose 2 cents to $94.80 a barrel at late afternoon Singapore time in electronic trading on the New York Mercantile Exchange. The contract fell $1.35 to settle at $94.78 in New York on Monday.
Brent crude for July delivery was up 10 cents at $111.10 per barrel in London.
This week, traders are worrying that Greece's inability to form a government after recent elections could worsen that country's debt crisis and recession, and undermine confidence throughout Europe.
"Greece's struggle to form a new government has moved to center stage," energy trader and consultant Ritterbusch and Associates said in a report. "The possibility of a significant economic slowdown in European economic activity is prompting contagion fears."
Oil investors are also taking their cues from global stock markets, which have slumped so far this month. The Dow Jones industrial average fell 1 percent Monday while Asian stock markets were mixed Tuesday.
In other energy trading, heating oil rose 0.3 cent to $2.93 per gallon and gasoline futures gained 0.8 cent to $2.97 per gallon. Natural gas fell 0.1 cent at $2.43 per 1,000 cubic feet.