SYDNEY (Reuters) -Shares of Australian-listed GQG Partners tumbled 13% on Monday after UBS downgraded the stock and said the firm may have lost A$600 million ($390 million) in funds under management in the two days following the indictment of Adani Group executives.

GQG is a major backer of Adani Group companies, whose founder Gautam Adani and seven other company associates have been indicted by U.S authorities on bribery charges. Adani Group says the allegations are baseless and has vowed to seek "all possible legal recourse".

UBS downgraded GQG from a buy to a neutral rating and reduced the stock's price target from A$3.30 to A$2.30. The shares were last trading at A$2.07.

The bank's analysts said their estimate of A$600 million in outflows over two days was based on a memo sent from GQG to investors.

They added that they were 'largely comfortable' with the investment perfomance implications for GQG from its Adani exposure.

However, the analysts also noted GQG had experienced weaker fund inflows during November before the Adani news and said the company was likely to experience slow funds growth in the near term.

GQG did not immediately respond to a request for comment on the analyst downgrade.

U.S. authorities have accused Gautam Adani, his nephew and executive director Sagar Adani and managing director of Adani Green Vneet Jaain, of being part of a $265 million scheme to pay bribes to secure Indian power supply contracts, and misleading U.S. investors during fundraisings.

Gautam Adani responded to the US indictment for the first time on the weekend in a speech where he said Adani Group had previously faced challenges and that the conglomerate was committed to "world class regulatory compliance".

($1 = 1.5392 Australian dollars)