U.S retail sales in May saw their sharpest monthly decline since November, weighed down by slower auto sales and lower prices at the gas pump, the government said Thursday.

The Commerce Department said overall retail sales slid 0.9 percent in May and a smaller 0.4 percent excluding autos. The drops were larger than Wall Street analysts had been projecting and cast some doubt on the strength of consumer demand entering the summer.

Consumer spending makes up two-thirds of economic activity and was a mainstay for the economy through the slump that began last year. Bond prices rose, the U.S. dollar eased and stock futures softened on the weak number.

Commerce said the overall drop was the largest since November's 2.6 percent slide. Declines were seen in various categories throughout the May report. Sales at auto and parts dealers dropped 2.5 percent while gas station sales fell a hefty 3.1 percent, their biggest fall since December, largely reflecting lower gasoline prices in the month.

The report was the second in as many days to show households pulling back on spending. On Wednesday, the Federal Reserve's anecdotal "beige book" report said U.S. retail sales were flat in late April and in May and that car sales in particular were mixed.

Analysts said Thursday's retail data, along with reports showing tame wholesale inflation and first-time claims for unemployment insurance, supported that notion.

"This certainly makes it unlikely for the Fed to move before September. Barring anything dramatic, it probably puts the Fed on the sidelines until September," said Rick Egelton, deputy chief economist with Bank of Montreal/Harris Bank.

April retail sales were unrevised at a 1.2 percent gain overall and changed to a 1.1 percent increase excluding autos. Initially April had been reported as a 1.0 percent advance outside of autos. Analysts polled by Reuters had expected May sales to fall 0.3 percent overall, but to have posted a 0.3 percent rise outside of the automotive sector.

While the economy fell into recession in the spring of 2001, consumer spending has held up relatively well.

However, the lack of a traditional burst of pent-up demand that usually accompanies the end of recessions raises the possibility the economy's recovery could be less robust than in previous bouncebacks, some economists and Fed officials say.

After growing at a blistering 5.6 percent annual rate in the first quarter of the year, growth is expected to have fallen back to a milder pace in the second quarter, leaving the Fed with little reason to raise interest rates soon.

Within the retail report, other categories posting declines included building materials, clothing, restaurants and bars and department stores. The 2.8 percent drop in apparel sales was the largest since September 2001.

The report did contain a few bright spots, however. Purchases of electronics and appliances bounced back in May, seeing a 2.1 percent increase after a 0.5 percent decline in April, and retail sales outside of autos and gasoline posted only a 0.1 percent decrease in May, a smaller drop than the overall decline.