Laboratory Corp. of America Holdings agreed to buy Covance Inc. for about $6.1 billion, creating a business that performs an unusual combination of routine medical tests and research for drug companies.

Covance shareholders will receive cash and stock valued at $105.12 a share, the companies said in a statement today. That’s 32 percent above Covance’s closing price Oct. 31. LabCorp shares fell the most since December 2013.

The two businesses have little in common. Convance will give LabCorp new sources of revenue and broaden its customer base, said Joe Herring, chief executive officer of Princeton, New Jersey-based Covance.

“There’s only 3 percent overlap between the companies,” Herring said on a call with investors today. “But the strategic opportunities between these two companies is absolutely stunning.” LabCorp shares fell 8.3 percent to $100.17 at 9:59 a.m. New York time.

Covance shares rose 25 percent to $100.05.

“We see this as LabCorp’s major move with regards to diversifying its business into a broader testing model,” said Michael Cherny, an analyst with Evercore ISI in Manhattan. “However, the cost of these moves is not free, and LabCorp paid a healthy multiple,” he said in a note to clients today.

LabCorp has a large database of patients that it can use to recruit people for clinical trials of drugs run by Covance, said David King, CEO of Burlington, North Carolina-based LabCorp.

“While we’re sensitive to the privacy aspects of that, it gives a tremendous recruiting tool to recruit and fill trials more rapidly,” King said on the call.

The acquisition also gave LabCorp access to Covance’s food and chemistry business, which tests food for nutrition content and safety, such as detecting harmful pathogens and food-borne illnesses.

King said the deal would also help LabCorp expand geographically. Currently, 100 percent of its revenue comes from the U.S., according to data compiled by Bloomberg.

Lazard, BofA Merrill Lynch, and Wells Fargo Securities LLC advised LabCorp. Sullivan & Cromwell LLP and Hogan Lovells are LabCorp’s legal counsel. Goldman Sachs & Co. is serving as financial adviser to Covance, Cravath, Swaine & Moore LLP is its legal counsel and Covington & Burling LLP is serving as its antitrust counsel.