Sibneft shares rose to a record yesterday after the majority owners of Russia's sixth largest oil producer said that they will cut their stake to seventy five percent, from eighty eight percent, selling shares worth more than $1.3 billion by 2005. The shares rose as much as 11 cents, or 5.3 percent, to $2.20. Brunswick UBS Warburg is the managing a sale of one percent of Sibneft to non-US investors that is due to close today. Cutting that stake to seventy five percent could more than double the amount of Sibneft shares readily available on the market, boosting the stock's attractiveness to investors by making it easier to buy and sell the shares. It also could boost the role of minority investors by letting them block major asset sales or purchases.