DreamWorks Animation SKG Inc. is planning layoffs of several hundred employees as box office troubles continue to plague the company, according to media reports. The Los Angeles Times, citing unnamed sources not authorized to speak publicly, reported on Tuesday the Glendale studio was planning layoffs of up to 400 people at facilities in Glendale and Redwood City, or about 20 percent of its 2,200 total employees. The cuts are expected to include animators, story-board artists and other production personnel and support staff, the Times story reported. A DreamWorks spokesman said the company was not commenting “on rumor and speculation.” DreamWorks last made staffing cuts two years ago when it delayed production of the movie “Me and My Shadow” and sent it back into development. At that time, the Glendale campus was expected to lose 250 to 350 people. This latest round of layoffs happens shortly after a management shakeup amid disappointing box office results and a series of write-downs, most recently $57 million on “Mr. Peabody and Sherman,” released in the spring. The studio’s fall release, “Penguins of Madagascar” has also underperformed and may result in another loss. Early this month Bonnie Arnold and Mireille Soria were named as co-presidents of feature animation as replacements for Bill Damaschke who served as chief creative officer since 2011. The one bright spot for the studio was “How to Train Your Dragon 2” that brought in $177 million in domestic box office grosses and $441 million in international receipts. “Dragon” won the best animated feature film award on Jan. 11 at the Golden Globes. Shares closed down $1.60, or 7.2 percent, to $20.56 on the Nasdaq.