WASHINGTON: The US economy grew slower than initially estimated in the fourth quarter as government spending contracted more sharply and consumer spending was less robust, a government report showed on Friday. Gross domestic product grew at annualized rate of 2.8 percent, the Commerce Department said in its second estimate, marking a downward revision from its initial 3.2 percent estimate. The economy expanded at a 2.6 percent rate in the third quarter. For the whole of 2010, the economy grew 2.8 percent instead of 2.9 percent.