TOKYO, April 15 (Reuters) - Microsoft backed artificial intelligence startup OpenAI made a pitch for business in Japan on Monday as it opened its first Asia office in Tokyo.

The startup, which has caused excitement among consumers since the launch of its ChatGPT generative AI chatbot in late 2022, is looking to grow new sources of revenue globally.

OpenAI CEO Sam Altman and Chief Operating Officer Brad Lightcap have hosted of hundreds Fortune 500 company executives in the United States and Britain this month to pitch for business, Reuters has reported.

Altman last year said he was considering a Japan location after meeting Prime Minister Fumio Kishida. The startup has also opened offices in London and Dublin.

Japan hopes to take advantage of AI as it looks to compete with an increasingly assertive China, accelerate the shift to digital services and alleviate deepening labour shortages.

OpenAI on Monday said it has a custom model optimised for the Japanese language and that Tadao Nagasaki, who was president of Amazon Web Services in Japan, is heading the Japan business.

While the country is seen as a laggard in the technology, local companies including telcos SoftBank and NTT are investing in large language models.

Microsoft said last week it would invest $2.9 billion over two years in cloud and AI infrastructure in Japan, part of a wave of investment globally by U.S. tech giants. (Reporting by Sam Nussey; Editing by Christopher Cushing)