November 16/Irving, Texas/Calgary Herald-- Hostess Brands says it is going out of business, closing U.S. plants that make Twinkies and Wonder Bread and laying off all of its 18,500 workers.

The Irving, Texas, company says a nationwide worker strike crippled its ability to make and deliver its products at several locations.

Hostess had warned employees that it would file a motion in U.S. Bankruptcy Court to unwind its business and sell assets if plant operations didn't return to normal levels by Thursday evening.

The privately held company filed for Chapter 11 protection in January, its second trip through bankruptcy court in less than a decade.

"Many people have worked incredibly long and hard to keep this from happening, but now Hostess Brands has no other alternative than to begin the process of winding down and preparing for the sale of our iconic brands," CEO Gregory F. Rayburn said in a letter to employees posted on the company website.

He added that all employees will eventually lose their jobs, "some sooner than others."

Hostess Brands has bakery operations across the United States but several of its brands are made for the Canadian market by other companies.

George Weston Ltd. of Toronto (TSX:WN) counts Wonder Bread among its brands while Montreal-based Saputo has rights to the Hostess brand but doesn't include Twinkies among its current lineup of snack cakes.

Thousands of members of the Bakery, Confectionery, Tobacco Workers and Grain Millers International Union went on strike last week after rejecting in September a contract offer that cut wages and benefits. Hostess said Friday the company is unprofitable "under its current cost structure, much of which is determined by union wages and pension costs."

A union representative did not immediately return a call from The Associated Press seeking comment on the company's announcement.

Hostess has said that production at about a dozen of the company's 33 plants has been seriously affected by the strike. Three plants were closed earlier this week.