US crude prices for March delivery rose $1.76 to $73.65 a barrel by 1:32 p.m. EST (1832 GMT) after hitting a high of $74.15. At the end of last week, prices briefly dipped below $70 a barrel to the lowest level since mid-December.
ICE Brent crude rose $1.86 to $71.97.
By midday Tuesday, the US dollar was off a recent 8-1/2 month high against the euro.
Spot gold hit a session high of $1,083.05 an ounce and was bid at $1,077.25, up 1.27 percent.
In midday US stock market trade, the Standard & Poor's 500 stock index was up 1.41 percent at 1,071.68 while the Dow Jones industrial average was up 1.71 percent at 10,078.21.
Stocks in Europe, however, missed out on much of the Greek developments and closed flat after having gained early on thinner speculation about a bailout for the fiscally strapped euro zone member.
In Europe, the FTSEurofirst 300 rose 0.17 percent to 979.33, although year-to-date losses are around 6 percent.
World stocks as measured by MSCI rose 1.1 percent, lifted mainly by gains of 1.96 percent in their emerging market component. Chinese and Hong Kong shares were generally higher, cheered by higher commodity prices.
Japan's Nikkei Nikkei edged down 0.2 percent to a two-month closing low.
