Kolkata, Jun 29 (IANS): Former Lok Sabha Speaker Somnath Chatterjee, under treatment in a private nursing home here following a cerebral haemorrhage, is gradually improving.

"There has not been any further deterioration in his condition. He is gradually improving," Pradip Tondon, CEO of Bellevue clinic, told IANS over phone.

The 89-year-old was admitted to the nursing home on Monday in a critical condition. He is now being treated by a "big medical board" comprising his family physicians and other specialists, Tondon said.

The medical board is led by Sukumar Mukherjee, he said.

News of Chatterjee's condition was kept under wraps over the first couple of days following a request from the family, sources said.

Chatterjee, regarded as an outstanding parliamentarian, served as Lok Sabha Speaker from 2004 to 2009.

The 10-time Lok Sabha member was expelled from the Communist Party of India-Marxist on July 23, 2008, "for seriously compromising the position of the party" as he refused to resign as the Lok Sabha Speaker after the CPI-M withdrew its support to the first United Progressive Alliance government over the Indo-US Civil Nuclear Deal.