Daniel Kretinsky says West Ham have been provided with much-needed certainty after it was confirmed he will become the club's largest shareholder.
Kretinsky has struck a deal with the Hammers' remaining shareholders, including former chairman David Sullivan, over the 25% of the club owned by the Gold family that will take his stake up to 46%.
The deal has ended former Newcastle director Amanda Staveley's immediate hopes of investing in the Championship club.
"I am deeply honoured to have the opportunity to become the largest shareholder of this great club," said Czech businessman Kretinsky.
"I appreciate the responsibility this brings and do not take it lightly.
"I would like to thank all continuing shareholders for their constructive efforts to enable this outcome and provide the club with the certainty it needs at this critical time."
There has been criticism of Staveley from senior West Ham figures given the ownership uncertainty spread from the middle of summer beyond a transfer deadline seen as being of critical importance in the club's quest to secure an immediate return to the Premier League.
The solution does, however, mean Sullivan will increase his stake in the club from 38.8% to 40%, even though he resigned as chairman in June. He said he intended to fight allegations made against him in a joint BBC Panorama and Times investigation.
Co-chair Vanessa Gold previously agreed to sell a portion of her shares to Kretinsky in the wake of the allegations against Sullivan being made public.
However, earlier this summer, she announced an agreement to sell her entire stake to Staveley.
That triggered a complicated pre-emption rights agreement at West Ham, which gave existing directors first refusal on any significant share sale.
A third major shareholder, Tripp Smith, will increase his ownership to 11%, with the remaining shareholders holding 3%.
Sullivan's status at West Ham is already being looked at by the independent regulator, although it is understood this latest move will not trigger further examination.
"The IFR's enquiries into the suitability of David Sullivan under our ODSE [owners, directors and senior executives] regime are active and ongoing and we are in touch with relevant authorities as part of this process."
Both Kretinsky and West Ham say they will not comment further until the formalities around the deal are completed, which is expected to be done inside a month.
