Alice A. Ruth will join private equity firm Quadrangle Group as managing principal and CIO of subsidiary Quadrangle Asset Management, according to a spokesman. Its a new position. Quadrangle Group launched the asset management business in December to manage private money, principally the personal wealth of Michael Bloomberg, New York City mayor and founder of Bloomberg LP. Ms. Ruth was the CIO of the $6 billion Gordon and Betty Moore Foundation. Information about her replacement was not available at press time.