Brij Mohan Khaitan was known in global tea fraternity as the "evergreen tea man of India".

Veteran industrialist and Williamson Magor Group patriarch Brij Mohan Khaitan died today at his residence here. He was 92.

He was suffering from old-age ailments, according to company sources. A widower, he is survived by his younger son, Aditya, and daughter Divya Jalan.

Mr Khaitan had recently resigned as Chairman of the group's flagship companies - dry cell battery maker Eveready Industries and tea producer McLeod Russel, citing his old age. He became Chairman Emeritus for both the companies.

West Bengal Chief Minister Mamata Banerjee expressed her condolences.

"Saddened at the passing away of noted industrialist BM Khaitan Ji. He was a much respected elder statesman of the business community of Bengal. My condolences to his family, his colleagues and his friends," Ms Banerjee said in a tweet.

Born in a family of lawyers (Khaitan & Co), Mr Khaitan, who was known in global tea fraternity as the "evergreen tea man of India", had made his tea empire in Assam and extended the business geography to Uganda, Rwanda and Vietnam.

Lauded as "a clear visionary" and one of the most humanitarian industrialists" of modern India, Mr Khaitan made the tea industry Indian-owned in the era after Independence.

From a mere supplier of tea chests and fertilisers to the Williamson Magor company, he joined its board after his family became a saviour to the tea planter when a crisis loomed over the company in 1961.

At that time, B Bajoria, an investor, acquired nearly 25 per cent stake in the Bishnauth Tea Company, the flagship firm but the Khaitan family provided the money to buy out Bajoria's stake and BM Khaitan was invited to join the board. Later, in the face of stiff resistance, he went on to become Managing Director of the Group.

In 1987, the Guthrie family, then the majority shareholder in the McLeod Russel Group, decided to sell their tea plantations in India. Mr Khaitan negotiated with them and bought their estates, to make the Williamson group the world's largest private tea producer.

The Indian Tea Association described him as "one of the last stalwarts in the tea industry amongst the old guard".

"Our deepest condolences to the bereaved family... Members of the Indian Tea Association deeply condole the passing away of BM Khaitan, Chairman emeritus MRIL, this morning. His demise marks the end of an era and loss of a leader and guide for the Indian Tea Industry. May his soul rest in peace," the association said in a tweet.

A Bachelor of Commerce from Calcutta University, Khaitan, better known as BMK, came to the limelight in the early 1990s as he had fought a long battle with Nusli Wadia's Bombay Dyeing to acquire Eveready. It was considered as one of the largest corporate takeovers in those days.

According to industry doyens, it was BMK's entrepreneurship zeal and business acumen that has put the Khaitans' business empire at the peak of tea, batteries and engineering businesses.

"He was one of the business promoters who saw business and social welfare together and actively supported many social initiatives. Khaitan was widely acknowledged to be a gentleman. His group companies scaled new heights under his leadership," Indian Chamber of Commerce Director General Rajeev Singh said. Mr Khaitan had been the chamber's President in 1973.

However, at the time of his demise, the group companies -- Eveready Industries, McLeod Russel, McNally Bharat Engineering -- have been stressing on reducing debt at the group level.