Alterra Capital Holdings Ltd said its New Point IV sidecar has closed with more than $200 million of capital commitments.New Point IV was established to provide greater additional capacity to write property catastrophe collateralised retrocessional coverage.Initially, Bermuda-based re/insurer Alterra and private-equity group Stone Point Capital LLC each committed $75 million of capital to New Point IV.In addition, New Point IV has closed with commitments from six other investors to increase New Point IV’s total capitalisation to more than $200 million.Aon Benfield Securities acted as an adviser to New Point IV.