After hitting nearly three-year highs Wednesday, the Dow Jones Industrial Average edged up 14.15 points (0.11 percent) to 12,705.11 in the first hour of trade.
The broad-market S&P 500 rose 0.41 points (0.03 percent) to 1,356.07.
The tech-rich Nasdaq Composite however fell 3.01 points (0.10 percent) to 2,866.87, pulling back from its highest closing level in more than 10 years.
Before the market's opening bell, the Commerce Department reported a slowdown in economic activity in the first quarter, to 1.8 percent annual growth in gross domestic product from 3.1 percent in the fourth quarter, in line with market expectations.
US growth slowed sharply as governments slashed spending, the Commerce Department reported.
A 7.9 percent cut in federal government spending, and a 3.3 percent cut in spending by local authorities, were factors in the slowdown.
After growth hummed at a 3.1 percent in the fourth quarter of 2010, the department's first estimate for the January-March period showed weakness in the recovery from the 2008-2009 recession.
"Things have cooled off a bit this morning, but certainly not for a lack of good earnings news," said Patrick O'Hare of Briefing.com.
ExxonMobil on Thursday reported bumper quarterly profits of nearly $11 billion as the energy giant benefited from a politically sensitive surge in oil prices.
Net income hit $10.65 billion in the first quarter, a leap of 69 percent from the year-ago period, the company said in a statement.
Exxon shares fell 0.6 percent.
Meanwhile US consumer products giant Procter & Gamble said net profit rose 11 percent in its third quarter as sales increased in all its regions around the world.
The firm's shares fell 0.6 percent.
The Labor Department's latest report on the sick US jobs market weighed on sentiment. New claims for unemployment insurance benefits surged more than expected last week to 429,000, the highest level since January.
US equities rallied Wednesday after the Federal Reserve left ultra-low interest rates unchanged and signaled it would keep supporting the fragile recovery.
The bond market was also mixed. The yield on the 10-year Treasury was steady at 3.32 percent. The 30-year Treasury yield fell to 4.43 percent, from 4.46 percent on Wednesday.
Bond yields and prices move in opposite directions.