FedEx Corp. (FDX) isn't lowering its legal guard despite two recent court victories regarding the employment status of its delivery drivers, a company executive said Wednesday.

"I don't expect plaintiff attorneys to fold up their tents and go away," said Rodger Marticke, chief operating officer of FedEx Ground, speaking during a Robert W. Baird & Co. conference.

Still, he voiced optimism the two cases will carry "significant precedent value" and help FedEx Ground defend itself from a swath of lawsuits challenging its use of independent contractors as drivers.

Last month, a federal appeals court sided with FedEx Ground that its drivers were properly classified as independent contractors, a blow to efforts by the International Brotherhood of Teamsters to organize them.

The Teamsters union previously has vowed to continue pushing its legal case, and a Teamsters executive reiterated the intention Wednesday.

"The Teamsters' fight on behalf of these workers will not stop," Teamsters Vice President Ken Hall said in a prepared statement. "We remain committed to those FedEx drivers who have sought the protection of a legitimate collective bargaining agreement to improve their lives."

Earlier in April, a Seattle jury ruled in a separate case that 320 drivers weren't illegally denied overtime pay because they were properly classified as independent contractors.

Marticke, whose comments were broadcast over the Internet, said Wednesday he hopes the two cases - one in a state court and one in federal court - will eventually help settle the legal wrangling in FedEx's favor once and for all.

But he indicated the fight is likely to continue, saying "there are people out there who would like to unravel this model" for a variety of reasons.

In addition, FedEx Ground doesn't have an unblemished record in defending its independent-contractor model. Late last year, FedEx agreed to pay $26.8 million to settle a California lawsuit after a state court ruled that 203 current and former drivers were employees and not contractors.

FedEx shares recently fell $2.41, or about 4.4%, to $52.71.

-By Bob Sechler, Dow Jones Newswires; 512-394-0285; bob.sechler@dowjones.com