MOSCOW (AFP) - Saudi Arabia is close to signing a two-billion-dollar deal to buy Russian arms, a Russian defence industry source was quoted as saying on Saturday. Work is nearly complete on a set of contracts on the delivery of Russian arms and military technology to Saudi Arabia, with a total value of around two billion dollars, the source told Interfax news agency. For many of these contracts, all the technical and financial details have practically been agreed, for others work is still ongoing, he added. Riyadh may purchase up to 150 helicopters - 30 Mi-35 attack helicopters and up to 120 Mi-17 transport helicopters - more than 150 T-90S tanks, around 250 BMP-3 infantry fighting vehicles and several dozen air defence systems, the source said. Contracts for the sale of the tanks and the helicopters could be signed as soon as this year, he told Interfax. Spokespersons for Rosoboronexport, Russias state-owned arms export monopoly, and for the Federal Service for Military-Technical Cooperation, which oversees the arms trade, could not be reached for comment on Saturday. Saudi Arabia a close US ally - has long bought most of its arms from the United States and Western Europe, but in recent years has been in talks on buying military equipment from Russia. Meanwhile Russia is keen to find new markets for its weapons exports, one of the few sectors of Russian manufacturing that has enjoyed international success. In 2008 Moscow and Riyadh signed a military cooperation treaty, and this year Saudi King Abdullah received a delegation that included a top Kremlin adviser and an official from Rosoboronexport.