Retailers boosted inventories by 0.3 percent. That reflected gains in many categories but declines at auto dealers. Manufacturers raised inventories by 0.1 percent. The latest reports provide fresh figures showing that the economy was not performing as well as previously thought at the turn of the year. Analysts said the slowdown in retail sales in January was not too worrisome given that it followed a 1.2 percent surge in December sales. On Wall Street, the Dow Jones industrial average closed at a new high. The Dow closed up 87.01 points at a new record of 12,741.86. It was the 28th record close since the start of October. A string of weaker-than-expected numbers is causing economists to reduce their estimates for overall growth, as measured by the gross domestic product, for the final three months of last year. They now believe that the GDP was growing at an annual rate of just 2.5 percent, a full percentage point below the government’s initial estimate of 3.5 percent GDP growth in the final quarter of 2006. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! WASHINGTON – Retail sales, hurt by a big drop in auto purchases, slowed at the start of the year and business inventories turned in the poorest showing in 17 months. The Commerce Department reported Wednesday that retail sales essentially were flat in January, the poorest performance since a 0.2 percent decline in October. Business inventories, the department said, basically were unchanged in December at $1.37 trillion, $147 million less than in November. It was the weakest showing for inventories since they fell by 0.4 percent in July 2005. The inventory report included a 0.5 percent plunge in stockpiles held by wholesalers.