* J&J sales lower than Wall Street's consensus forecast
* Weaker U.S. dollar boosts commodity prices
* Analyst Whitney downgrades Goldman Sachs to neutral
(Updates with analyst quote)
By Edward Krudy
NEW YORK, Oct 13 (Reuters) - U.S. stock index futures turned mostly lower on Tuesday as Johnson & Johnson's third-quarter sales figures disappointed investors, offsetting a lift from higher commodity prices that rose with the weaker U.S. dollar.
Johnson & Johnson, the world's largest healthcare company by market value, posted a higher-than-expected profit and raised its full-year earnings outlook, but its sales came in lower than Wall Street's consensus. The shares slipped 2 percent before the bell.
"It's all going to be about earnings, and it's all going to be about top-line growth," said Dave Rovelli, managing director of U.S. equity trading at Canaccord Adams in New York. "All anyone cares about is if these guys are going to beat on the top line."
S&P 500 futures fell 1.6 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures fell 13 points and Nasdaq 100 futures fell 0.5 points.
Crude oil and metal prices rose as the dollar slipped 0.3 percent against a basket of major currencies, helping shares in miners and energy companies.
Rick Meckler, president of LibertyView Capital Management in Jersey City, said the weak dollar and low interest rates could prove an unsustainable stimulus for equities.
"Its going to be very difficult for this market to wean itself of the lure of those two items and the stimulus effect you get from both," he said.
A weak dollar helps U.S. equities by boosting overseas revenue of U.S. companies and lifting commodity prices.
Prominent U.S. banking analyst Meredith Whitney downgraded her rating on Goldman Sachs Group Inc to "neutral" from "buy," and the shares fell about 1.5 percent to $187.09.
Intel Corp, the world's largest chip maker and a bellwether for the technology sector as well as an indicator of business demand, is set to report earnings after the bell.