A broad decline in US stocks following a slump in Europe and weak corporate earnings reports

U.S. stocks are moving lower in midday trading following steep declines in Europe and some disappointing results from big companies.

Investors are worried about Greece's shaky finances and news from China Friday that regulators would tighten rules on borrowing by investors to buy stocks following big gains this year.

In the U.S., American Express slumped 5 percent after reporting revenue that missed analysts' forecasts.

The Dow Jones industrial average slumped 249 points, or 1.4 percent, to 17,857.

The Standard & Poor's 500 lost 21 points, or 1 percent, to 2,083. The Nasdaq fell 69 points, or 1.4 percent, to 4,938.

European stocks, which have also rallied this year, fell. Germany's DAX slumped 2.6 percent. Investors piled into German government bonds, which are perceived as being safe, sending yields lower.