* Walmart said this month will buy 77 pct of the Indian firm
* First public exit by SoftBank's private equity fund
* Value of SoftBank's investment up 60 pct in less than a year (Adds details of SoftBank's investment strategy)
TOKYO, May 23 (Reuters) - SoftBank Group Corp said on Wednesday it is selling its roughly 20 percent stake in Indian e-commerce firm Flipkart to Walmart Inc , the first public divestment by its Vision Fund.
Walmart said this month it will pay $16 billion for a stake of around 77 percent in Flipkart and there had been some uncertainty over whether the Japanese tech and investment giant would remain a shareholder.
SoftBank did not disclose terms of the sale but this month CEO Masayoshi Son said its investment in the Indian firm was worth around $4 billion. The Vision Fund invested invested $2.5 billion in Flipkart in August last year.
It also did not comment on its reasons for cashing out. The Flipkart exit comes far more quickly than SoftBank's average investment duration of 13.5 years.
The Vision Fund has invested $30 billion in startups in the last year. Son, who, as of last May, has attracted $93 billion to his technology investment vehicle, said last week he is looking to start a new fund - potentially further upending the world of dealmaking.
Major investments by the fund include ride-hailing firm Uber Technologies, co-working space provider WeWork Cos and chip designer Arm Holdings. (Reporting by Sam Nussey; Editing by Muralikumar Anantharaman and Edwina Gibbs)