NEW YORK (CNN/Money) - Stocks could have some trouble at the start of the last day of a strong quarter Friday.

U.S. stock futures were slightly down, indicating a narrowly lower opening for stocks. Stocks had started the morning lower, then briefing indicated a positive open before falling again after a weaker than expected personal income and spending report.

Personal income fell 0.1 percent in August, rather than the 0.3 percent gain that had been forecast by economists surveyed by Briefing.com. Personal spending also fell 0.5 percent, steeper than the decline of 0.2 percent that had been expected.

The major indexes go into the last day having made solid gains over the last three months, with the Dow Jones industrial average up 2.7 percent, Nasdaq up 4.1 percent and the Standard & Poor's 500 up 3.1 percent.

David Kelly, economic advisor for Putnam Investments, said he thinks the downward pressure on stocks Friday is related more to end-of-the quarter moves by portfolio managers than by any bad news hanging over the markets.

"There's nothing particularly ominous about the economic data we're looking at today," he said. "As we head to end of the quarter there may be managers who are adjusting their portfolio."

Kelly said he thinks that stocks and the economy both have a relatively good outlook for the fourth quarter, saying that companies should be able to post strong third quarter earnings in the coming weeks, despite the effects of hurricanes Katrina and Rita and the higher energy costs that followed them.

"If we we're going to see problems, I think we would have seen them (in earnings warnings) in the last week or two," he said. "I think pretty rapidly positive earnings surprises will overtake earnings warning as the story."

"A crucial issue is how fast the price of gasoline comes down," Kelly added. "If you can get the price of gas down before Thanksgiving, that will give us a strong holiday shopping period, and that could help the market."

Oil prices fell early Friday. The November light crude futures contract for NYMEX slipped 41 cents to $66.38 a barrel in electronic trading, while the November contract for Brent crude lost 55 cents to $63.29.

Major markets in Asia closed mixed Friday, while major European markets were higher in early trading.

Treasury prices were little changed, with the yield on the 10-year note yielding 4.29 percent. The dollar gained ground against on the euro and the yen.

Other economic reports due Friday include after-market open readings consumer sentiment and manufacturing strength in the Chicago region.

The revision of the University of Michigan consumer confidence survey is expected to come in at 78, which would be up from the 76.9 reading at the middle of the month. The Chicago PMI survey of manufacturing executives is expected to rise to 52.0, showing growth in the sector there after a 49.2 reading in July that indicated a slight contraction.

In corporate news, machinist union members at aircraft maker Boeing (Research) ratified this past weekend's tentative contract agreement and started returning to work Thursday night. Shares of the Dow component were up nearly 1 percent in early trading in Frankfurt Friday.

Shares of another Dow component, tobacco giant Altria (Research) were down $1.15, or 1.6 percent, in pre-market trading on Inet after the Supreme Court of Canada rule late Thursday that provinces there can sue the tobacco industry for the health costs of smoking, clearing the way for suits that could cost the industry as much as $70 billion according to some estimates.

For a more detailed look at the markets before the open, click here.