India's Reliance Retail is in talks with existing investors including the sovereign wealth funds of Singapore, Abu Dhabi and Saudi Arabia for combined new investments of around $1.5 billion, three sources with direct knowledge of the plan said.

Reliance Retail is India's largest retailer and is led by Asia's richest person Mukesh Ambani. The talks with investors are part of an internal target to raise $3.5 billion which the company wants to close by the end September, Reuters has reported. Of that, QIA last month announced a $1 billion investment and KKR & Co this week $250 million.

Singapore's GIC, the Abu Dhabi Investment Authority (ADIA) and Saudi Arabia's Public Investment Fund (PIF) are looking to invest at least $500 million each in Reliance Retail at a valuation of $100 billion, one of the sources told Reuters.

GIC, ADIA declined to comment, while PIF did not respond to Reuters requests for comment. Reliance said: "we do not comment on media speculation and rumours".

A second source said some of the three investors could end up putting in less than $500 million, and talks were also on with at least one or two further investors for the fund raising.

"All the three investors have evaluated the company quite seriously," said the first of the three sources, all of whom declined to be named as the discussions are private.

The final investments or funding plans could still change.

GIC, PIF and ADIA are among the world's biggest investment funds and together they own a 4.4% stake in the Indian retailer.

Reliance Industries, the retail arm's parent, also has plans to invest in the ongoing fund raising round of $3.5 billion, two of the sources said.

Reliance sold a 10.09% stake in its retail unit in 2020, valuing it at 4.68 trillion rupees ($56.4 billion). At that time, GIC and ADIA invested $664 million each, while PIF pumped in $1.15 billion, based on current exchange rates. (Reporting by M. Sriram and Aditya Kalra; Additional reporting by Yantoultra Ngui in Singapore; Editing by Alexander Smith)