SAN FRANCISCO — Fitbit Inc., hit with two lawsuits from rival Jawbone Inc. in two weeks, is assuming a fighting stance.

The San Francisco-based company said Wednesday it has turned to lawyers at Orrick, Herrington & Sutcliffe and Gibson, Dunn & Crutcher to lead its defense of the suits, which come as Fitbit prepares for its initial public offering.

Jawbone jacked up its litigation campaign against Fitbit on Wednesday with a patent suit claiming the company's entire catalog of fitness-tracking devices steps on Jawbone technology.