Senior Iranian officials invited Russian oil firms to contribute a share to the development of other Iranian projects after they excluded Gazprom Neft - the oil arm of Gazprom - from the Azar oilfield development plan due the Russian company\'s stalled operation.Managing-Director of the National Iranian Oil Company (NIOC) Ahmad Qalebani said Saturday that Russian companies can participate in the development of Iranian oil fields such as Changooleh in Iran\'s southern oil rich region. Last week, the NIOC signed a contract worth 1.9 billion US dollars with a domestic consortium to develop the Azar oil field in Iran\'s western province of Ilam replacing Russia\'s Gazprom. The contract was inked with the local contractors after Russia\' s Gazprom failed to implement the project, Qalebani said.