The Ontario Teachers' Pension Plan Board (OTPP; French: Régime de retraite des enseignantes et des enseignants de l'Ontario or RREO), is an independent organization responsible for administering defined-benefit pensions for school teachers of the Canadian province of Ontario. The OTPP also invests the plans pension fund, and is one of the world’s largest institutional investors. The plan is a multi-employer pension plan, jointly sponsored by the Government of Ontario and the Ontario Teachers' Federation. OTPP was established on Jan. 1, 1990. Until then, Ontario teachers' pensions had been sponsored solely by the Ontario government. Assets of the plan had been invested in government bonds only. Today, the OTPP administers the pensions for some 183,000 teachers, principals, and school administrators, and pays pensions to some 133,000 retirees. In 2015, $5.5 billion in benefits was paid to members. Ontario Teachers' is headquartered in Toronto, with operations in London, Hong Kong and an office in New York.