U.S. stock futures turned sharply lower Tuesday after three Dow components issued disappointing earnings and forecasts.

Futures were already pointing to a lower open as news surrounding Spain unnerved investors.

The euro fell below the key $1.30 level after ratings agency Moody's downgraded five of Spain's regional governments, including Catalonia -- the largest. And the gross domestic product for Spain, which has been mired in recession for months, fell by 0.4% in the third quarter from the second quarter, according to data released Tuesday from the Bank of Spain.

European stocks were lower in midday trading. Britain's FTSE 100 fell 1.2%, the DAX in Germany lost 1.4% and France's CAC 40 declined 0.8%.

With no data on the U.S. economy, investors were focused on the latest quarterly reports from Corporate America.

Shares DuPont fell 5% ahead of the bell after the Dow component reported weaker-than-expected quarterly earnings and announced plans to cut 1,500 jobs worldwide. Another Dow component, United Technologies, reported better-than-expected earnings but missed on revenue and lowered its revenue forecast for next year.

Economic bellwether and Dow component 3M reported earnings that were in line with forecasts, but the company missed revenue estimates and pulled back on its guidance.

UPS, another economic bellwether, reported results that were roughly in line with expectations.

After the bell, Facebook and Netflix will release their reports.

Analysts at S&P Capital IQ predict third-quarter earnings for companies in the S&P 500 will grow by just 0.04% overall this quarter, the worst since the third quarter of 2009.