At 1400 GMT the Dow Jones Industrial Average had added 25.62 points (0.21 percent) at 12,196.18.
The broader Standard & Poor's 500 rose 2.42 (0.18 percent) to 1,312.08, while the tech-focused Nasdaq composite added 7.30 (0.27 percent) to 2,743.72.
"Better-than-forecasted earnings from Oracle Corp. and Accenture Plc are helping the markets extend the week's gains, despite continued euro-area debt concerns, Middle East tensions, and the nuclear crisis in Japan," said analysts at brokerage Charles Schwab.
Oracle shares added 3.1 percent after their fiscal third quarter earnings came in above analyst estimates, as they said revenues were growing at a 36 percent annual rate in the period.
Accenture shares jumped 5.5 percent after they beat earnings forecasts by 5.6 percent and predicted strong growth in the coming quarter.
The markets were also buoyed by the Commerce Department's revision of fourth quarter expansion. That pushed the full-year growth figure slightly up to 2.9 percent, after 2009's contraction.
But it also showed that cutbacks to government spending at all levels -- but mainly state and local -- are holding back growth.
Bond prices rose, pushing the yield on the 10 year Treasury down to 3.39 percent from 3,40 percent late Thursday. The 30 year note fell to 4,46 percent from 4.47 percent.
Bond prices and yields move in opposite directions.