New Delhi, June 22 -- A long-simmering family feud at Sun TV Networks Ltd has burst into the open, with former Union minister Dayanidhi Maran mounting a legal challenge against his elder brother, chairman and managing director Kalanithi Maran, over how he acquired a 75% controlling stake in the Rs.23,000-crore broadcast conglomerate.

In a legal notice dated 10 June, Dayanidhi has questioned a series of transactions executed between 2003 and 2005 - years when Sun TV was still a privately held company - alleging that Kalanithi quietly consolidated ownership while the family was grappling with a personal crisis. At the time, their father, former Union minister Murasoli Maran, was critically ill and subsequently passed away in 2003.

The leg...