Johannesburg (Reuters) - South African casino operator Gold Reef Resorts said on Monday it had failed to win approval from gambling authorities for a proposed private equity buy-out by Friday's deadline, ending the 9.85 billion rand (USD 1.32 billion) deal. Gold Reef said in September last year a consortium known as Bidco, including South African private equity firm Ethos Private Equity and Goldman Sachs, will pay 34 rand per share for the group.