Businessman Alexandre Gaydamak - son of a Russian billionaire - is to become joint owner of Portsmouth after coming to a deal with chairman Milan Mandaric.
Mandaric plans to spend more time with his family
The struggling Premiership club said in a statement French national Gaydamak, 30, whose father is Arcadi Gaydamak, would be an equal partner in the club.
Financier Arcadi Gaydamak already owns Israeli club Beitar Jerusalem.
Pompey stressed the future boardroom change would have no effect on manager Harry Redknapp's position.
"Contrary to press reports there is no question of Harry Redknapp's position as manager of the club being under threat," said the statement.
"He will have the full backing of Mr Alexandre Gaydamak and will continue to enjoy the full support of Milan Mandaric."
The Pompey statement gave no financial details regarding the new partnership.
"The pair of them will work together closely to further develop all aspects of Portsmouth Football Club, Pompey stadium, Pompey village as well as a modern training facility," said the statement.
Redknapp says he will get on with his job as usual after he saw Pompey lose 2-1 away at Blackburn to stay in the Premiership relegation zone.
Redknapp said: "I came here to work for chairman Milan Mandaric really and we had a chat this morning, but I don't really know what's happening yet.
"I will get on with my job and whatever will be, will be.
"If someone comes in and that means we can improve the playing squad, that is clearly the most important thing."
As with all incoming directors, Gaydamak will be subject to the Football Association's 'fit and proper person test' so until he passes that, the deal cannot officially go through.
But assuming he passes, he is expected to take on more of a hands-on role at Fratton Park, with Mandaric stepping back to spend more time with his family.
Despite owning Beitar, Alexandre's father Arcadi has lived in Moscow since 2002.
The Beitar owner is involved in various industrial enterprises in Russia and owns a medium-sized bank and brokerage company.
In 2000 Paris magistrates issued an arrest warrant for him for questioning over an alleged arms-for-oil deal with Angola in the early 1990s.
Arcadi Gaydamak insisted his involvement in the deal was as part of a legitimate agreement between the governments of Russia and Angola.
Jean-Christophe Mitterand, the son of former French president Francois Mitterand, was given a 30-month suspended sentence for his involvement in the affair.