2011 retail sales are a record $4.7 trillion

The gain of nearly 8% over 2010 is the largest percentage increase since 1999.

America’s retailers enjoyed a record 2011 and the first months ever in which sales topped $400 billion. But the final month of the year was a dud.

Sales eked out a 0.1% increase in December to a seasonally adjusted $400.6 billion.

It was the second straight month that sales topped $400 billion. The government revised November sales to show a 0.4% gain, twice the original estimate.

December’s increase, though, was the weakest in seven months. Excluding volatile auto purchases, overall sales fell 0.2%. It was the first such drop since May 2010.

But analysts said they still expect consumers to help the economy strengthen further, especially because businesses have stepped up hiring. More jobs mean more people with money to spend.

“Although consumer spending is not particularly robust, households do continue to spend and provide moderate support for the overall economy,” said Steven Wood, chief economist at Insight Economics.

For all of 2011, sales totaled a record $4.7 trillion. That was a gain of nearly 8% over 2010 — the largest percentage increase since 1999.

Steady sales gains have fueled a 20% surge from the low during the Great Recession. Monthly sales are even 6% above their pre-recession high. The figures confirm evidence that the economy was strengthening as 2011 ended.

Part of the reason for December’s weak showing was lower gasoline prices, which reduced sales at gas stations. Excluding gas stations, retail sales would have risen 0.3% in December.

Another factor was heavy discounting during the holiday shopping season. Many retailers said they had to cut prices in December to attract shoppers.

The sluggish retail-sales data followed a report this week that consumers raised their borrowing in November by the most in a decade. Many consumers might have charged more spending to their credit cards because their pay has stagnated. The savings rate has also declined.