The US economy grew at an annual rate of 2.7% in the first three months of 2010, slower than previously estimated.
The Commerce Department had previously estimated growth at 3% versus the same period in 2009.
The new figure is disappointing as it is only the third quarter since the US economy stopped contracting, and in past recoveries growth has been faster.
Markets took the news in their stride, with the dollar little-changed, and New York shares opening slightly up.
Business investment and consumer spending - important components of GDP - were both revised down.
However, inventory adjustments were revised up.
Following a recession, companies typically spend money rebuilding their stock of goods for sale - a transitory process that boosts GDP growth in the early stage of a recovery.