Russian Billionaire Mikhail Fridman's investment group A1 said that it considers legal action against the merger of Tele2's Russian unit and state-run bank VTB.

Tele2 agreed to sell its Russian unit to VTB in a $3.5 billion deal. Fridman's A1 countered that deal by offering $3.6-$4 billion cash.

A1 said that it has the right to buy the Tele2 unit, stressing that there were a number of meetings it had with the Tele2 management last year during which it made higher offer than what has been agreed with VTB.

A1's managing director Dmitry Vozianov said in a statement that their lawyers are working on whether or not they file a legal case against the VTB deal.

Possible legal action could claim a failure to executive fiduciary duties and lost opportinuties, A1 added.

VTB defended that its bid for Tele2's unit is legal.