The Tax Ministry is investigating how Yukos used tax-optimization methods to cut its tax bill, a French newspaper quoted Finance Minister Alexei Kudrin as saying Friday.

The report extended a decline by Yukos shares and compounded speculation that an $11 billion merger with rival Sibneft would fall apart and that its licenses were at risk in an all-out attack on the company by the state.

The battered shares plunged nearly 8 percent on the day to close at $10.26. The stock has lost 29 percent of its market value since major shareholder Mikhail Khodorkovsky was arrested in late October.

"The street talk is that people think this merger is possibly off the rails, which I think for a while people couldn't fathom," Brunswick UBS trader Nick Mokhoff said.

Kudrin was quoted by La Tribune as saying Yukos had cut its taxes by $5 billion using tax-optimization arrangements, including ones which were legal.

A report by Interfax on Wednesday quoted a Tax Ministry letter alleging that Yukos may owe up to 150 billion rubles ($5.1 billion) in back taxes. Yukos has denied any wrongdoing.

"All I can say right now is that Yukos has cut its taxes by $5 billion by using tax-optimization practices, including legal ones," Kudrin told La Tribune.

"Everybody who has tried to avoid paying taxes and thought justice would leave him in peace must be punished. Our primary concern is to put an end to tax avoidance."

Yukos' woes began in July when a key shareholder was arrested on charges of tax evasion. Khodorkovsky was arrested about two months ago on similar charges.

Many analysts believe the judicial assault on Khodorkovsky, who resigned as CEO shortly after his arrest, was orchestrated by the Kremlin, which is said to be determined to cut the politically ambitious oil tycoon down to size.

Last week, smaller oil company Sibneft said it was suspending the merger and analysts say Yukos management was under intense pressure from Sibneft's owners to give Sibneft operational control.

n Group Menatep chairman Platon Lebedev's lawyer Yevgeny Baru was searched by guards and had documents confiscated as he left a meeting with his jailed client, Interfax reported Friday, citing Baru.

Guards at Matrosskaya Tishina prison searched Baru after he visited Lebedev, Interfax said. Baru said he was not given a copy of a record of the search, Interfax said. The confiscated documents were not directly related to the case against his client, he told the news service.

Lebedev is in custody awaiting trial on charges of fraud and tax evasion which he denies. Menatep owns 44 percent in Yukos.

Khodorkovsky is also being held at Matrosskaya Tishina on fraud and tax evasion charges. Khodorkovsky denies the charges.

(The Moscow Times 08.xii.03)