Viz Media, one of the leading publishers of manga in the U.S., announced a sweeping round of layoffs Tuesday that will effect every part of the company. Sources tell PW that as many as 55 people were laid off at Viz’s San Francisco headquarters and it appears its small New York office, which had about 5 staffers, has been closed. The number of staff released represents about 40% of the employees at Viz Media.

After years of booming sales the U.S. , the manga industry seems to have hit the wall. While the category is still one of the largest in the graphic novel market, overall sales declined by 20% in 2009 according to figures compiled by pop culture news site ICv2.com, the second year in a row in which manga sales declined.

In a formal statement, the company confirmed the layoffs although a company spokesperson declined to respond to specific questions about the numbers of emplyees released. In the statement, Viz acknowledged that it is “restructuring to adjust to changing industry and financial market realities,” and said it “had to refine its workforce by eliminating certain positions and making cuts in other areas.” The statement goes on to say that “we are of course saddened by these departures,” but that “we feel confident that with these changes, Viz Media will be more streamlined and able to withstand the climate of the economy at this time.”

In an update to its original statement released the following day, Viz took pains to assure fans that their favorite titles and series will not be cancelled in the wake of these layoffs. “We have no plans at this time for drastic measures such as product cancellations or business line closures. Your favorite series are not going away.”