Microsoft Corp said on Monday it would invest more in OpenAI, staking its future on the startup and technology behind the chatbot sensation ChatGPT and setting the stage for more competition with its rival Alphabet Inc's Google.

"Today, we are announcing the third phase of our long-term partnership with OpenAI through a multiyear, multibillion dollar investment to accelerate AI breakthroughs to ensure these benefits are broadly shared with the world," the software giant said in a blog post.

(Reporting By Jeffrey Dastin in Palo Alto, Calif.; Additional reporting by Eva Mathews in Bengaluru; Editing by Krishna Chandra Eluri)