NEW YORK (REUTERS) - US stocks started the fourth quarter on a subdued note, weighed down by healthcare and consumer stocks.

The S&P 500 healthcare index fell 0.7 per cent, the most among the 10 major S&P indexes that were lower, due to declines in Pfizer and Merck.

Consumer staples fell 0.59 per cent, dragged down by Procter & Gamble and PepsiCo.

The Purchasing Managers' Index (PMI) from the Institute of Supply Management showed that factory activity expanded in September after having contracted in August.

Investors are also on the lookout for news from Deutsche Bank, which is working to reach a settlement with US authorities who have demanded a fine of up to US$14 billion (S$19 billion) from the bank for mis-selling mortgage-backed securities.

While the bank's Frankfurt-listed stock was not trading due to a public holiday, its US-listed shares were down 1.2 per cent at US$12.96 on Monday.

The travails of Germany's biggest lender has unsettled investors who are now awaiting third-quarter corporate earnings and the upcoming US presidential election. "It looks like a quiet start to the day and that's not surprising," said Art Hogan, chief market strategist at Wunderlich Equity Capital Markets in New York.

At 9:37 a.m. ET (9:37 p.m Singapore time), the Dow Jones Industrial Average was down 79.3 points, or 0.43 per cent, at 18,228.85.

The S&P 500 was down 7.33 points, or 0.34 per cent, at 2,160.94 and the Nasdaq Composite was down 8.31 points, or 0.16 percent, at 5,303.69.

The S&P 500 index showed two new 52-week highs and three new lows, while the Nasdaq recorded 23 new highs and seven new lows.