A method of controlling the regeneration of spent catalyst from an oxygenate-to-olefin reaction zone in order to provide a partially regenerated catalyst. The partially regenerated catalyst has between 1 to 4, or 1 to 3, or, 2 to 3 wt % coke. The regeneration is controlled by adjusting a ratio of air to recycled flue gas in the combustion gas passed to the regeneration zone. CO in the flue gas is removed in a CO oxidation zone which receives oxygen to oxidize CO to CO2.