US STOCKS-Wall St edges lower, S&P down for third straight session

* Indexes: Dow off 0.5 pct, S&P 0.4 pct, Nasdaq down 0.3 pct

By Ryan Vlastelica

NEW YORK, Sept 23 (Reuters) - U.S. stocks were modestly lower on Tuesday, with the S&P 500 on track for its third straight daily decline as investors digested signs of slowing global growth.

The day's losses were slight but broad. All ten primary S&P 500 sectors fell on the day, with consumer staples the weakest on the day, off 0.8 percent. Energy stocks were the relatively best performers, down less than 0.1 percent as crude oil rose 0.9 percent.

Wall Street's losses tracked Europe, which was down after data showed a contraction in French business activity and slower growth in German manufacturing this month.

The European data "is a little concerning," said David Lebovitz, global market strategist for J.P. Morgan Funds in New York. "We didn't expect things to improve there forever and always, but we are seeing a bit of a slowdown, which is weighing a bit."

The Dow Jones industrial average was falling 80.19 points, or 0.47 percent, to 17,092.49; the S&P 500 was losing 7.69 points, or 0.39 percent, to 1,986.6; and the Nasdaq Composite was dropping 11.92 points, or 0.26 percent, to 4,515.77.

The largest percentage gainer on the New York Stock Exchange was Millennial Media Inc (NYSE: MM - news) , which was rising 12.99 percent, while the largest percentage decliner was CarMax Inc (NYSE: KMX - news) , down 10.07 percent.

Among the most active stocks on the NYSE were Bank of America Corp, up 0.65 percent to $17.14; U.S. shares of Grupo Aval Acciones Y Valores, up 1.11 percent to $13.65 and Rite Aid Corp, up 3.52 percent to $5.29.

On the Nasdaq, Yahoo Inc (NasdaqGS: YHOO - news) was up 0.4 percent at $38.80, Apple Inc (NasdaqGS: AAPL - news) , up 1.4 percent at $102.52 and Sirius XM, up 0.1 percent at $3.53 were among the most actively traded.

Declining issues were outnumbering advancing ones on the NYSE by 2,039 to 946, for a 2.16-to-1 ratio on the downside. On the Nasdaq, 1,742 issues were falling and 880 advancing for a 1.98-to-1 ratio favoring decliners.

The benchmark S&P 500 index was posting 2 new 52-week highs and 9 new lows. The Nasdaq Composite was recording 18 new highs and 107 new lows. (Editing by Andre Grenon)