In this morning trading in New York, US benchmark crude for August delivery was up 90 cents to USD 98.89 after rising as high as USD 99.17. The only other time oil rose above USD 99 this year was June 19, when it reached USD 99.21.
In London, Brent crude was up 51 cents at USD 103.51 a barrel on the ICE Futures exchange.
Protests in Egypt continued, as President Mohammed Morsi faced a military ultimatum that gives him until tomorrow to meet the demands of the millions who have taken to the streets seeking his ouster.
Traders are also awaiting the Energy Department's weekly report on US stockpiles of crude oil tomorrow.
Data for the week ending June 28 is expected to show a draw of 3 million barrels in crude oil stocks, according to a survey of analysts by Platts, the energy information arm of McGraw-Hill Cos.
That would be the first decline in four weeks, and the forecast is supporting oil prices.