Nearly 10% of Walter Investment Management Corp.'s employees will lose their jobs after it closes Ditech's Irving, Texas, office, a notice filed with the Texas Workforce Commission said.

A total of 437 positions are being eliminated, according to the notice, which was also addressed to Irving Mayor Rick Stopher.

Walter had about 4,500 employees at the end of the first quarter, down from nearly 5,900 at the end of 2015.

The notice, required under the Worker Adjustment and Retraining Notification Act, was dated July 12, the same day Walter CEO Anthony Renzi sent a memo to the company's employees announcing the closure. Companies are required to provide 60 days' notice if they plan mass layoffs of more than 50 workers along with office closings.

There were some layoffs at the Irving office on the day of the announcement, with "terminations expected to continue on a schedule through Dec. 31, 2017," the letter, signed by Elizabeth Monahan, senior vice president, chief human resources officer, said.

"Due to current circumstances, management has determined it is in the best interests of the company to consolidate our mortgage servicing operations in company locations other than Irving and close this facility," the letter said.

Walter ultimately intends to consolidate its operations into three "core" Ditech sites in Fort Washington, Pa., Jacksonville, Fla., and Tempe, Ariz., as well as one core site in Houston for the Reverse Mortgage Solutions business it acquired in 2012. Walter also acquired reverse mortgage lender Security One Lending in 2013, but the company stopped originating reverse mortgages at the beginning of this year and now only services the loans.

Walter is evaluating options for its eight other locations, which have been deemed "legacy" sites. The review process for the legacy offices should be completed by late 2017 or early 2018 and "could result in additional site closings or other outcomes," the Renzi memo stated.