San Francisco, Nov 30 : Sam Altman has officially returned to OpenAI as CEO after an intense drama earlier this month, with Microsoft getting a non-voting observer seat on the company's board. OpenAI's new board consists of chair Bret Taylor, Larry Summers, and Adam D'Angelo, the only remaining holdout from the previous board. Microsoft is a major investor in OpenAI, with a 49 percent stake in the for-profit entity that the nonprofit board controls, reports The Verge. In a memo to employees, Altman said that he harbours 'zero ill will' towards Ilya Sutskever, OpenAI's co-founder and chief scientist who was behind Altman's ouster. 'While Ilya will no longer serve on the board, we hope to continue our working relationship and are discussing how he can continue his work at OpenAI,' Altman said in the memo. 'The fact that we did not lose a single customer will drive us to work even harder for you,' he told employees. He said that OpenAI will advance research plan and further invest in its full-stack safety efforts. 'Our research roadmap is clear; this was a wonderfully focusing time. I share the excitement you all feel; we will turn this crisis into an opportunity! I'll work with Mira (Murati) on this,' Altman said. OpenAI board chair Taylor told employees that they are thrilled that 'Sam, Mira and OpenAI President and co-founder Greg Brockman are back together leading the company and driving it forward'. 'We will build a qualified, diverse board of exceptional individuals whose collective experience represents the breadth of OpenAI's mission ' from technology to safety to policy. We are pleased that this Board will include a non-voting observer for Microsoft,' he added. Altman was earlier fired as CEO of OpenAI, the developer of AI chatbot ChatGPT, and the earlier board had said it "no longer has confidence in his ability to continue leading OpenAI.' Later, Microsoft Chairman and CEO Satya Nadella announced to hire Altman and Brockman to help the company pursue its advanced AI dreams with a new vertical. /IANS