(This September 7 story corrects to Fitch Group, not rating agency Fitch, in first paragraph)

By Krishna N. Das

NEW DELHI (Reuters) - CreditSights, part of the Fitch Group, said it had discovered calculation errors in its recent debt report on two power and transmission companies controlled by India's richest person, Gautam Adani, after a conversation with the management.

Debt research firm CreditSights' report late last month calling the conglomerate "deeply overleveraged" and flagging other risks had sent shares of many Adani companies down.

In a report dated Sept. 7, CreditSights said that it had spoken with Adani Group's finance and other executives and reconciled some figures for Adani Transmission and Adani Power.

"(Adani's) Management views that the group's leverage is at manageable levels, and that its expansion plans have not been mainly debt funded," CreditSights said.

But CreditSights said on Thursday it still had concerns about the Adani group's overall debt levels.

For the Adani group as a whole, "we still stand by our original financial calculations and credit ratios, which leads us to remain concerned over the Adani Group's leverage," CreditSights said in an email to Reuters.

The Adani Group said on Thursday debt ratios of its companies "continue to be healthy and are in line with the industry benchmarks of the respective sectors". Adani also said that over the past decade, the group had worked to improve its "debt-metrics through our capital management strategy".

Shares of Adani Transmission and Adani Power closed up around 1% each on Thursday, while five other group companies ended lower in a broadly positive Mumbai market.

For Adani Transmission, CreditSights corrected its earnings before interest, tax and amortisation (EBITDA), or core profit, estimate to 52 billion rupees ($652.45 million) from 42 billion rupees earlier. For Adani Power, it corrected its gross debt estimate to 489 billion rupees from 582 billion rupees.

It did not give the period for the estimates.

The combined market value of the Adani Group's seven publicly traded companies - flagship Adani Enterprises, Adani Wilmar, Adani Ports, Adani Green Energy, Adani Transmission, Adani Total Gas and Adani Power - has increased about tenfold in the past three years to about $251 billion.

($1 = 79.7000 Indian rupees)

(Reporting by Abinaya Vijayaraghavan and Krishna N. Das; Editing by Rashmi Aich and Jane Merriman)