The giant accounting firm Arthur Andersen broke the law by shredding Enron Corp. documents, a U.S. jury decided over the weekend. The jury reached the verdict after deliberating for 10 days.

The jury didn’t buy Andersen’s argument that it destroyed the paper and computer files for routine “housekeeping” reasons.

The jury concluded Andersen was fully aware that a federal investigation was underway into its client when the records were destroyed. Disgraced energy-trading firm Enron was accused of hiding debts and concealing its imminent collapse from creditors and investors.

Andersen’s lawyers announced plans to appeal the conviction.

Andersen was once one of the world’s top five accounting firms. But over the past six months, it has has lost nearly two-thirds of its corporate clients and let go 7,000 employees.

Many of its foreign operations, including its Canadian division, have already been sold. Over 1,000 Andersen Canada partners and staff joined Deloitte & Touche LLP earlier in June.