* Hewlett-Packard profit forecast tops estimates
* Green Mountain tumbles on U.S. accounting inquiry
* Indexes down: Dow 0.4 pct, S&P 0.5 pct, Nasdaq 0.4 pct
* For up-to-the-minute market news see [STXNEWS/US] (Updates to open)
By Edward Krudy
NEW YORK, Sept 29 (Reuters) - U.S. stocks dipped on Wednesday on investor caution after a strong rally in September, but analysts said buying by mutual fund managers to adjust portfolios at quarter-end may lift equities.
Marc Pado, U.S. market strategist at Cantor Fitzgerald & Co in San Francisco, said the market was technically overextended, but a recent pattern of buying on dips could re-emerge as fund managers "window dress" their portfolios.
"Today we might see a little bit of strength," he said. "The market just kept unrelentingly marching higher, and the more it did that, the more it puts pressure" on fund managers to buy stocks.
The S&P 500 has climbed more than 9 percent since the beginning of the month on signs the economy may avoid a double-dip recession and on renewed hopes the Federal Reserve will take more steps to prop up the economy.
The Dow Jones industrial average <.DJI> dropped 39.13 points, or 0.36 percent, to 10,819.01. The Standard & Poor's 500 Index <.SPX> dropped 5.98 points, or 0.52 percent, to 1,141.72. The Nasdaq Composite Index <.IXIC> dropped 8.79 points, or 0.37 percent, to 2,370.80.
Over the past several sessions, near-term resistance for the S&P 500 appeared to be building at the 1,149 level, and if it does, it could bring investors back into both equities and options, said Scott Fullman, director of derivative investment strategy at WJB Capital Group in New York.
Hewlett-Packard Co
Family Dollar Stores Inc
On the downside, Green Mountain Coffee Roasters Inc