BASEL, Switzerland, Jan. 8 (Reuters) -- Central bank shareholders of the Bank for International Settlements voted unanimously on Monday to buy back all shares from private shareholders, ignoring threats of a legal challenge. The BIS, an international institution that serves as a bank to central banks, stuck by a plan to pay 6,000 Swiss francs per share for the 72,648 shares, or 13.73 percent, of its total capital its member central banks do not yet own, despite objections from some private shareholders. However, some private investors are not satisfied. SocGen First Eagle Fund has filed a complaint in Manhattan. BIS General Manager Andrew Crockett said BIS records showed the SocGen has 5,000 shares outstanding, but the company said it had 9,000 altogether. Separately, in the United States, gold analyst Reginald Howe has also filed a suit against the BIS alleging that it colluded with other central banks to depress the gold price. Howe also claims that the BIS is offering private shareholders less than fair value. Crockett said there were two further complaints in the pipeline. One of these comes from the French firm Deminor. Deminor has threatened a dozen top central bankers with legal action if they approve the buyback, saying they think the offer is 53 percent lower than the BIS's net asset value. Deminor's Fabrice Remon told Reuters, "This is an outlaw operation. There were no checks and controls. The central bankers have set the rules of the game to suit themselves. We're going to take this to the courts." He said Deminor would probably make its move as soon as next week. -END-