Medical testing giant Laboratory Corporation (NYSE: ) is launching a $500 million stock buyback plan.

The company said Monday morning that it has recently repurchased $131 million in stock and that $198 million of a previously authorized buyback approved by its board still remains.

“The Company intends to pursue an accelerated pace of repurchases to take advantage of the current share price which the Company believes does not fully reflect the value of the Company’s business or prospects,” LabCorp said in a statement.

LabCorp shares traded at $68.40, down 12 cents, in trading Monday.