By Ryan Vlastelica

NEW YORK (Reuters) - Weakening business activity worldwide is hitting U.S. companies where it hurts, with more of them signaling disappointing results than at any time over the past decade.

Many bellwether companies, including two Dow components, have come out in recent days with profit warnings, and the slowing in Europe has been cited as a major factor for those outlooks.

For every company that has raised its second-quarter profit outlook, 3.6 have warned, the worst ratio since the third quarter of 2001, according to Thomson Reuters data.

Firms including PepsiCo Inc , package shipper FedEx Corp and tobacco company Philip Morris all lowered earnings expectations in recent days, citing concerns about Europe.

On Wednesday, Procter & Gamble Co cut its growth forecasts for the second time in two months. The consumer products giant also reduced its profit view as it deals with slowing demand in Europe and China.

"It would be wise to be underweight multinationals with inordinately large exposure to Europe," said Steven Neimeth, a money manager at SunAmerica Asset Management in Jersey City, New Jersey.

"Stocks are reactively more negatively to these outlooks because investors are fearing the worst this coming year," said Neimeth, who helps oversee $9 billion.

While cautious outlooks can make it easier for companies to top consensus estimates, corporate commentary has done little to reassure investors.

Also on Wednesday, Bed Bath & Beyond Inc gave a weaker-than-expected quarterly profit outlook as it spends sooner than expected to improve its e-commerce business. It also said customers were buying a greater percentage of lower-margin goods.

Last week, United Technologies Corp executives said the downturn in Europe was worse than they had expected at the start of the year and that they were "very concerned" about the region's impact on its sales in Spain.

According to a recent survey by the Business Roundtable, U.S. chief executives' view of the economy dimmed in the second quarter, with fewer expecting to increase sales or add workers than three months earlier.

Analysts expect earnings for the Standard & Poor's 500 <.SPX> to show a 6.3 percent rise in the second quarter, down from the 9.2 percent increase forecast on April 1, according to Thomson Reuters data.

When profit powerhouse Apple Inc is excluded, growth edges down to 5.5 percent.

Much of this quarter's growth comes from the financial sector because of Bank of America Corp , whose mortgage settlement in the year-ago quarter caused a large loss. Excluding that company, the anticipated profit rise for the S&P 500 at large drops to 1.1 percent.

Financial-sector earnings are seen up 13.6 percent in the quarter. Excluding that group, analysts expect total S&P profits to be down by 0.5 percent.

"There's not much second-quarter growth expected at all because of the general economic slowdown and fears about Europe," said Greg Harrison, corporate earnings research analyst with Thomson Reuters in New York. "Companies are taking a more cautious outlook now than they were even during the financial crisis."

U.S. stocks had their worst day in three weeks on Thursday on mounting evidence that slowing manufacturing growth worldwide threatened corporate profits.

Semiconductor stocks weighed on the Nasdaq after chipmaker Micron Technology Inc posted a net loss for the fourth straight quarter.

And after the market closed, Moody's Investors Service cut the credit ratings of 15 of the world's biggest banks in an expected move that was part of a broad review of major financial institutions.

"All of the banks affected by today's actions have significant exposure to the volatility and risk of outsized losses inherent to capital markets activities," Moody's Global Banking Managing Director Greg Bauer said in a statement.

Also on Thursday, trucking and logistics company Ryder Systems Inc cut its quarterly earnings forecast, citing lower demand for its commercial rental services.

Questions continue to swirl about Greece's prospects and slowing expansion in China, adding to concerns about bond yields in Spain.

(Editing by Lisa Von Ahn)