LOS ANGELES & PARIS--(BUSINESS WIRE)--OpenGate Capital ("OpenGate"), a global private equity firm, announced today that its portfolio company Sargent and Greenleaf ("S&G") has completed the sale of Premier Steel Doors and Frames ("Premier" or the "Company"), a US manufacturer of hollow metal doors and frames, metal building door systems, and aluminum windows, to ASSA ABLOY, the global leader in access solutions with leading positions in efficient door openings, trusted identities and entran