Polygon Investment Partners has signed a joint venture with GreenOak Real Estate, a new company set up by former Morgan Stanley real estate head John Carrafiell, in a move that sees the firm continue reinventing itself from a multi-strategy fund to a multi-fund boutique.

Tetragon Financial Group, a $909m (€685.7m) listed fund managed by Polygon, has bought a 10% stake in GreenOak, which was formed by Carrafiell and two of his Morgan Stanley colleagues: Sonny Kalsi, the former global head of the real estate investing business, and Fred Schmidt, who previously was head of the real estate investing business for Asia.