William Lyon Homes Inc. filed for Chapter 11 bankruptcy protection on Monday, along with more than 20 companies affiliated to the Newport Beach-based homebuilder.

The company filed for bankruptcy in Delaware, listing more than $600 million in liabilities.

William Lyon Homes counts assets of about $593 million, including real estate valued at about $485 million, according to court records.

The bankruptcy had been expected for about a month. The company plans to get court approval for a prepackaged restructuring plan that will cut its debt by about $182 million, while raising $85 million in new equity.

The company said the plan carries the support of its senior lender and more than 93% of its senior note holders.

“Today's action enables us to efficiently restructure our debt and create a capital structure that will provide a foundation for future growth,” Chief Executive General William Lyon said in a statement.

Gen. Lyon and his family took the company private in 2006, near the peak of the housing market. Following the restructuring, the Lyon family’s stake in the company will fall from nearly 95% to about 20%.