The head of Russian oil group Russneft has said he is quitting the firm and selling it to a Kremlin-friendly rival.
Mr Gutseriyev is giving up his share in one of Russia's top 10 oil firms
Mikhail Gutseriyev said "unprecedented persecution" from authorities had forced him to step down and sell up.
Aluminium tycoon Oleg Deripaska has now applied for regulatory approval to buy the group for an undisclosed amount.
The company is currently facing tax claims of around $1bn (£500m) and police charged Mr Gutseriyev with illegal business activities in May.
In an open letter in the Russneft company magazine, Mr Gutseriyev said there was "an attack on all fronts" against the firm from tax authorities, the prosecutor general's office and the interior ministry.
"They told me I could take the easy way out. I refused. Then to make me more ready to negotiate, my company came under unprecedented persecution," he added.
As a result, he said he had decided to quit and hand over control of the firm to a new owner he believed would resolve all of Russneft's problems over time.
Basic Element, the holding firm of Mr Deripaska, is expected to win approval within the next month to take over the firm in a deal rumoured to be worth about $6.5bn (£3.2bn).
Mr Deripaska is widely seen as loyal to the Kremlin and has previously said that he would sell his aluminium assets to the state if he was asked.
Commentators have likened the plight of Mr Gutseriyev to that of former Yukos boss Mikhail Khodorkovsky who is currently serving an eight year jail sentence in Siberia for tax evasion.
Oil giant Yukos was carved up after being hit with claims for $28bn in back taxes, with state oil giant Rosneft later buying up most of the company.
Yukos has argued that the tax demands made by the government were tied to a political campaign against Mr Khodorkovsky.