MUMBAI, Jan 23 (Reuters) - A 75 billion rupee ($816.58 million) debt sale by India's Adani Power was corned by large Indian banks and mutual funds, who bought over 90% of the issue, three sources aware of the matter said on Friday.

Domestic banks and mutual funds invested 69.75 billion rupees as part of the issue, the bankers said, declining to be identified as they are not authorised to speak to the media.

Adani Power did not respond to an email seeking details of the bond issue, which closed for bidding on Friday.

India's Adani group firms shed $12.5 billion in market cap on Friday, after the U.S. markets regulator asked a court for permission to personally email summons to founder Gautam Adani and group executive Sagar Adani over alleged fraud and a $265 million bribery scheme.

The group has focused its borrowings mainly in the domestic market after shortseller Hindenburg Research made allegations around its corporate governance practices in 2023.

Adani Power raised 28.60 billion rupees via two-year bonds and 26.90 billion rupees via a three-year note. The remaining 6.75 billion rupees and 12.75 billion rupees were raised through four- and five-year papers.

The Adani unit will pay a coupon of 8.00% and 8.20% on the two- and three-year bonds, and 8.30% and 8.40% on four- and five-year papers.

SBI mutual fund, India's biggest in terms of assets under management, led the buying and invested 25 billion rupees, or one-third of the issue size, while Kotak Mutual Fund bought 6 billion rupees of debt, the bankers said.

ICICI Bank bought 11 billion rupees of bonds, while Axis Bank opted for 10 billion rupees of notes, they said.

SBI Mutual Fund, ICICI Bank and Axis Bank did not respond to emails seeking comment.

Trust Investment Advisors, ICICI Bank and Axis Bank are the arrangers for the issue.

Trust Investment Advisors did not respond to an email seeking comment.

The bonds are rated 'AA' by Crisil and India Ratings, with the coupons set to step up by 25 basis points for every notch of rating downgrade.

($1 = 91.8470 Indian rupees)

(Reporting by Dharamraj Dhutia and Khushi Malhotra; Editing by Ronojoy Mazumdar)

By Dharamraj Dhutia and Khushi Malhotra