Wellspring Capital Management LLC, a New York-based private equity investment firm, has entered into a definitive agreement to acquire Horsham, Pa., based International Mill Service, Inc. from a shareholder group led by GSC Partners. Terms of the deal were not disclosed.

GSC Partners initially invested in International Mill Service in 1999, and became its majority shareholder in 2001.

The transaction will close after required approvals have been obtained under the Hart-Scott-Rodino Act and other customary closing conditions.

Wellspring Capital Management LLC is a New York-based private equity firm that manages over $1.0 billion in equity capital. The firm is focused on acquiring companies where it can realize substantial value by contributing management expertise, innovative operating and financing strategies and capital.

International Mill Service is a leading provider of outsourced industrial services, primarily to the steel industry. Services include slag processing, metal recovery, materials handling, scrap management, surface conditioning (scarfing) and a wide range of specialty services.

GSC Partners is a registered investment advisor with over $7 billion of assets under management. The firm specializes in control distressed debt investing, European mezzanine lending and structured finance. GSC Partners, with over 90 employees, has offices in New Jersey, New York and London. GSC's investors include both institutional investors and substantial net worth individuals seeking sophisticated and attractive alternative investing opportunities.