Retail, mining, and railroad shares carried most American stocks to their third straight advance on growing confidence the Federal Reserve will assuage turmoil in credit markets and keep the economy growing.

Lowe’s Cos., the second-largest home-improvement retailer, climbed the most in four years after its profit topped analysts’s estimates. Freeport-McMoRan Copper & Gold Inc., the world’s second-biggest copper producer, gained following a rally in metal prices. Union Pacific Corp., the largest American railroad, posted its biggest one-day increase since March 2006 after UBS AG said it may be able to raise prices.

The Dow Jones Industrial Average rose 42.27, or 0.3%, to 13,121.35. The Nasdaq Composite Index added 3.56, or 0.1%, to 2,508.59. The S&P 500 slipped 0.39, or 0.03%, to 1,445.55. More than seven stocks climbed for every six that fell on the New York Stock Exchange.

“Investors are relieved that the Fed’s becoming more proactive in dealing with the credit crisis,” a manager of about $65 billion in assets as chairman of Reserve Funds in New York, Bruce Bent, said.

Yesterday’s advance added to the S&P 500’s biggest rally in four years after the Fed lowered its discount rate on August 17 and said it will “act as needed” to keep credit market losses from spreading. Yields on American Treasury bills fell the most in two decades on speculation the Fed will cut its benchmark rate next month.

“The earnings scenario this quarter has been quite positive, but it’s being completely overlooked by investors,” a manager $2.4 billion with Bryn Mawr Trust Co. in Bryn Mawr, Penn., Eric Thorne, said. “There’s some opportunity there for investors. The fundamentals are being overlooked.”