U.S. wholesale inventories climbed in March as businesses saw a sharp increase in sales, suggesting parts of the economy are growing firmly, according to Commerce Department data released Tuesday.

Inventories rose 1.1 percent in the last month of the first quarter, slightly above economists' forecasts. But sales jumped 2.9 percent, more than double the median projection in a Reuters poll.

At $392.01 billion, sales were at their highest since June 2008, just as the U.S. credit crisis was morphing into a broader phenomenon that pushed the world into recession.

The sales to inventory ratio, which offers some hints of the state of demand, fell to 1.13, matching June 2008 lows. The U.S. economy expanded just 1.8 percent in the first quarter, but is expected to grow around 3 percent for 2011 as a whole.