Prices have soared since October as two of the market's biggest fears — an unraveling of the 17-nation eurozone and another recession in the U.S. — appear to have eased — at least for now.
On Friday benchmark crude rose $1.11 to $98.89 per barrel in midday trading on the New York Mercantile Exchange. In London, Brent crude increased 33 cents to $114.04.
Greece and Italy have new political leadership to help them deal with massive debts. Greece appointed former European Central Bank Vice President Lucas Papademos as its new prime minister, and an interim cabinet was sworn in Friday. And Italy approved crucial economic reforms that were demanded by the European Union. Italy will also be getting a new prime minister.
Stock markets rose as well, with the major indexes up about 2 percent.
A rise in oil prices to $100 per barrel is a key milestone, indicating that the economy can afford to pay those prices.
"It's a sign of confidence that we're not going to flip back into recession," PFGBest analyst Phil Flynn said. "It's also sending a message that we better conserve supplies or find new sources of oil."
Oil and gasoline supplies have been falling this year, and continued declines could force oil prices even higher.
Gasoline and other petroleum-based fuels will likely rise if oil pushes past the $100 mark and higher. Already, the $3.44 per gallon national average is the highest ever for this time of year, and analysts say pump prices are likely to return to $4 per gallon ($1.05 a liter) in the spring.
In other Nymex energy trading on Friday, heating oil rose 3 cents to $3.1822 per gallon, and gasoline futures fell 2 cents to $2.6209 per gallon. Natural gas fell 5 cents to $3.60 per 1,000 cubic feet.