Vladimir Romanov has increased his shareholding in Hearts to 55.5% and is targeting complete control of the Edinburgh club.
Romanov has brought immediate success to Hearts
The Lithuanian businessman is offering 35 pence per share, which values the Tynecastle club at approximately £4.2m.
And chairman George Foulkes urged all shareholders to take up the offer.
He said: "We are top of the SPL because of Vladimir's involvement and I think we can become even more successful with his role changing to owner."
Romanov became the largest shareholder of the current SPL leaders in February, taking over 29.9% of the club.
Now Foulkes, Stewart Fraser, SMG and HBOS plc have agreed to pass on their combined 25.6% of shares.
He is now compelled by market regulations to make an offer for all the remaining stock.
Romanov said: "I believe that Hearts has the potential to develop into a major player within European football.
"And that we can build the current business, both on and off the field, into a club in which the supporters and the city of Edinburgh can have pride.
"By means of the offer, we hope to consolidate control in order to continue our investment in the business and achieve our stated objectives.
"Looking to avoid the factionalism and conflict with shareholders is one of the reasons why I sought to acquire an increase in my shareholding."
If Hearts go into private ownership, they would save £250,000 a year - the cost of being a fully listed company.
That would require the backing of 75% of the club's shareholders.
Foulkes continued: "UBIG (the Lithuanian company chaired by Romanov) has given us assurances of their continuing involvement with the club and we believe this will enable us to continue our current progress.
"We have also obtained agreement that the current privileges of qualifying Hearts shareholders will be preserved through a loyalty club.
"The advantages are we can de-list from the Stock Exchange and that is a substantial saving in terms of money but also in terms of the rigmarole of having to report everything to the Stock Exchange.
"We can tell people more about what is happening at the club when we are not listed.
"It simplifies things as far as investment is concerned and it means that Vladimir Romanov can invest in the club and in players more easily."