Organizers of the new Institutional Life Services L.L.C. operation have signed another backer.

National Financial Partners Corp., New York, and the longevity markets group at Goldman Sachs Group Inc., New York, announced the formation of ILS in September.

The firms now report that Senior Financial Inc., a “wholly owned venture investment subsidiary” of Genworth Financial Inc., Richmond, Va., has agreed to become an ILS minority shareholder.

The organizers have described ILS as a “marketplace” that will bring institutional investors and seller representatives together.

Genworth Institutional Life Settlements Inc., a Senior Financial subsidiary, will get a 10% ownership interest in ILS and will hold one seat on the ILS board, according to Genworth.

A unit of Goldman Sachs and a unit of NFP each will have a 45% stake in ILS, Genworth says.

Organizers hope to launch ILS by March 31, 2008, Genworth says.