A kosher slaughterhouse has filed for bankruptcy court protection, blaming its financial difficulties on the May immigration raid on its Iowa plant in which more than 300 people were arrested.

Agriprocessors' petition for bankruptcy reorganization was filed Tuesday, a day before it was to meet in federal court with its biggest lender, First Bank of St. Louis.

The bankruptcy filing said Agriprocessors owes $50 million to $100 million to creditors, and estimated its assets at between $100 million and $500 million.

The plant was the site of a May 12 immigration raid in which 389 people, mostly Central Americans and Eastern Europeans, were arrested.

Agriprocessors said it is "actively seeking new sources of financing," and thinks it can restructure.

First Bank filed suit last week in U.S. District Court in Cedar Rapids claiming Agriprocessors was either unable or unwilling to meet its loan payments. It said the company overstated how much money it had available.

First Bank is seeking to foreclose on the Agriprocessors plant in Postville and appoint a third party to oversee the company's assets.

The bank's suit names Agriprocessors owner Aaron Rubashkin, his son and former CEO Sholom Rubashkin and slaughterhouses in Postville, Iowa, and Gordon, Nebraska. In addition to livestock and plant equipment, the suit says the Rubashkins' personal property should be considered collateral.

A lawyer for the company did not immediately return a call seeking comment.

The bankruptcy filing says Agriprocessors owes between 200 and 999 creditors.

Among the creditors is one of the plant's staffing firms, Jacobson Staffing, to which it owes $845,389.82. The Des Moines-based staffing company, which had served as the slaughterhouse's human-resources and recruitment arm, suspended its relationship with the company last week, but did not give a reason. The departure of the 450 Jacobson staffers last week left the slaughterhouse with about 250 workers.

The bankruptcy filing also lists a debt of $318,235 owed to the company's electricity supplier, Alliant Energy.