Niel and his companies will buy the stake from Kinnevik, the largest shareholder in Tele2, through Freya Investissement.
The transaction will take place in three steps with a first close of 2.9 billion crowns while the rest is conditional on regulatory approvals, Kinnevik said in a statement.
($1 = 10.3210 Swedish crowns)
(Reporting by Louise Breusch Rasmussen, editing by Anna Ringstrom and Terje Solsvik)