* Hewlett-Packard rises as profit forecast tops estimates
* Green Mountain tumbles on U.S. accounting inquiry
* Dow, S&P, Nasdaq nearly flat (Updates to midday, changes byline)
By Rodrigo Campos
NEW YORK, Sept 29 (Reuters) - U.S. stocks were little changed on Wednesday as investors grappled with mixed technical signals near the end of one of the best months for stocks in 20 years.
The S&P 500 has climbed 9 percent in September, traditionally a bad month for stocks, as concerns the economy may contract again eased, and more recently on hopes the Federal Reserve would take extra steps to lift the economy.
"Normally traders would be trying to short this market against the (recent rally)," said John Schlitz, chief U.S. market technician at Instinet in New York.
"It feels too overbought to go long short-term, but bad (economic) news yesterday took the market up anyway so traders are not too comfortable shorting either," he said.
The S&P 500's relative momentum index, which measures upward and downward changes, moved last Friday above 70, a level that indicates an overbought condition. It currently stands at 72.1.
The Dow Jones industrial average edged up 1.93 points, or 0.02 percent, to 10,860.07. The Standard & Poor's 500 Index shed 0.11 points, or 0.01 percent, to 1,147.59. The Nasdaq Composite Index gained 0.01 points, or 0.00 percent, to 2,379.60.
Stocks mostly rose on Tuesday despite a downbeat reading on consumer confidence and a mixed report on home prices.
The S&P 500 is on track to close the quarter up more than 11 percent after falling 11.9 percent in the second quarter. If the S&P ends September up more than 9 percent, it would be the fourth month it has done so since 1990.
Hewlett-Packard Co rose 2.5 percent to $42.68 after the computer and printer maker forecast 2011 profits above estimates.
Family Dollar Stores Inc gained 2.5 percent to $44.44 after the discount retailer recorded upbeat profits and issued a bullish outlook.
On the downside, Green Mountain Coffee Roasters Inc slid 15.5 percent to $31.29 after disclosing a regulatory inquiry into its accounting practices.
Over the past several sessions, near-term resistance for the S&P 500 appeared to build near 1,150, and a break above that could draw more investors into both equities and options, said Scott Fullman, director of derivative investment strategy at WJB Capital Group in New York.
Instinet's Schlitz said 1,150 is "a fair checkpoint," as it corresponds to January highs. But he said there is little strong resistance for the S&P before the 1,175 area.
Advancing stocks outnumbered declining ones on the New York Stock Exchange by a ratio of about 7-to-5, while on the Nasdaq, about 13 stocks rose for every 11 that fell.
About 3.4 billion shares traded at midday on the NYSE, the American Stock Exchange and Nasdaq.