Indian billionaire Gautam Adani will control 64.71% of New Delhi Television Ltd NDTV.NS as the company's founders have decided to sell most of their shares, four months after he launched a takeover of the news network.

Adani already held 37% of NDTV after an open offer and an acquisition of a company owned by founders Radhika and Prannoy Roy, despite several unsuccessful attempts by NDTV to block the takeover citing regulatory restrictions on moving shares.

The husband-and-wife team will sell a 27.26% stake in NDTV to Adani-owned entity AMG Media Network and retain a combined 5%, regulatory filings by NDTV showed on Friday.

"The AMG Media Network, after the recent open offer, is now the single largest shareholder in NDTV. Consequently, with mutual agreement we have decided to divest most of our shares in NDTV to the AMG Media Network," the founders said in a statement.

The ports-to-energy conglomerate's takeover of NDTV had raised fears among some journalists that one of the country's last bastions of free media was under threat. Ravish Kumar, a senior executive editor of NDTV, resigned soon after Adani acquired the entity backed by NDTV's founders.

"Since the open offer was launched, our discussions with Gautam Adani have been constructive; all the suggestions we made were accepted by him positively and with openness."

It was not immediately clear what the discussions and suggestions entailed. Radhika and Prannoy Roy did not immediately respond to requests for comment.

Founded in 1988 and owned by the husband-and-wife team, NDTV had previously said that the move by Adani "was executed without any input from, conversation with, or consent of the NDTV founders".

Adani in November told the Financial Times he sees the takeover of NDTV as a "responsibility" rather than a business opportunity, and that he had invited Prannoy Roy to remain as chair when the acquisition is completed.

The billionaire hails from the western state of Gujarat, the home state of Prime Minister Narendra Modi. India's main opposition Congress party has often accused Adani and other billionaires of getting favourable policy treatment from Modi's federal administration.

Shares of NDTV surged nearly 55% to a record high in the days following the announcement of Adani's takeover plans in August. They have shed all those gains since then.