Sovereign wealth fund Abu Dhabi Investment Authority (ADIA) is in advanced talks to invest $350 million to $400 million in India's Lenskart, valuing the eyewear retailer at $4.5 billion, the Economic Times newspaper reported on Monday.

The investment, which could give ADIA an almost 10% stake in Lenskart, is likely to be in the form of a secondary sale of shares, with a small primary round comprising growth equity, the report added, citing people aware of the matter.

The details on the investors that would dilute their stake, and by how much, were yet to be decided, the report said, adding an official announcement is expected in a couple of weeks.

ADIA, which currently does not have a stake in Lenskart, declined to comment. Lenskart did not immediately respond to a request from Reuters seeking comment.

Started in 2010, Lenskart's investors include U.S. private equity firm KKR & Co Inc, Japan's SoftBank Group and Singapore state investor Temasek Holdings.

Lenskart also operates in the United States, Singapore and the UAE. It has a manufacturing unit in the Indian state of Haryana and a yet-to-be-started fully-automated plant in the state of Rajasthan.

Earlier this year, Lenskart acquired a majority stake in Japanese eyewear brand Owndays, turning the Indian company into one of Asia's largest online retailers in the segment. (Reporting by Nandan Mandayam in Bengaluru; Editing by Savio D'Souza and Dhanya Ann Thoppil)