* U.S. should plan for more fiscal stimulus-Obama adviser
* Credit card delinquency soars, adding to worry over debt
* Indexes down: Dow 1.0 pct; S&P 0.9 pct; Nasdaq 1.0 pct (Updates prices, adds AmEx, Intel shares, context)
By Rodrigo Campos
NEW YORK, July 7 (Reuters) - U.S. stocks fell on Tuesday as investors turned cautious ahead of earnings season, and talk of a second stimulus package underscored worries about the U.S. economic recovery.
Signaling the economy's difficulty in rebounding from a deep recession, a member of the Obama administration's economic advisory panel said the United States should plan to possibly provide a second round of stimulus funds to prop up the economy.
"Talk of a new stimulus plan is actually a confidence killer," said Joseph Battipaglia, market strategist at Stifel Nicolaus in Yardley, Pennsylvania. "That would mean we've added a trillion dollars to debt without anything to show for it."
Investor concerns over mounting debt was also underpinned by a report showing cash-strapped consumers fell behind on their credit card bills in record numbers in the first quarter.
Shares of credit card company American Express Co shed 1.7 percent at $23.11 and the S&P Consumer Finance index fell more than 3 percent.
In the broader market energy stocks were among the biggest drags, along with other economically sensitive sectors like basic materials and industrials. Healthcare, a defensive play, was the only notable S&P sector with gains so far in the session.
The Dow Jones industrial average fell 83.13 points, or 1.00 percent, to 8,241.74. The Standard & Poor's 500 Index lost 8.01 points, or 0.89 percent, to 890.71. The Nasdaq Composite Index dropped 18.24 points, or 1.02 percent, to 1,769.16.
Investors also have their eyes set on the quarterly earnings season that gets underway this week, with Alcoa Inc set to report on Wednesday. Alcoa, a Dow component, is expected to post a third consecutive quarterly loss.
Stifel's Battipaglia said earnings are expected to disappoint. "The anticipation is that Alcoa's report will be even worse than expected," he said.
"The expectation of a speedy recovery is starting to slow because there is no evidence to support it."
The loss of confidence in the economic recovery has sent oil prices tumbling. New York crude fell close to 2 percent and its five-session slide has pressured energy stocks, a large sector of the S&P 500.
Oil services company Schlumberger Ltd fell 2.5 percent to $50.17 while blue-chip Exxon Mobil Corp lost 1.3 percent to $67.22.
The S&P energy sector index lost 1.6 percent.
On the upside, shares of chip maker Intel Corp rose 1.3 percent to $16.75 after Banc of America Securities-Merrill Lynch upgraded the U.S. semiconductor industry and five stocks in the sector, including Intel, saying recent data suggested emerging signs of a turn in end demand.
But the PHLX semiconductor index shed 0.4 percent.
The broad S&P 500 index rallied about 40 percent from 12-year lows hit in early March on expectations of a speedy economic recovery. But the rally wilted in the last month, as investors sought stronger evidence that conditions were improving.