Laboratory Corporation (NYSE: LH) shares fell more than 6 percent Thursday after the international medical testing firm cut its profit forecast.

Shares fell more than $4.50 to trade at just over $67 a share in late-afternoon trading. LH closed at $66.87, down $4.78, or 6.7 percent.

The stock traded at its lowest level in two years.

LabCorp said a slowing economy would reduce profits and also increase bad debts.

LabCorp reduced its annual profit target range to $4.54-$4.66 from $4.74-$4.90 as part of its second quarter earnings report. Revenues will increase from 10.2-11.3 percent instead of 13-14.3 percent, the company added in a statement.

A year ago, LabCorp, reported second-quarter earnings of $1.05 on profits of $128.7 million. In the second three months of this year earnings fell to 92 cents or $104.2 million.