KYIV, Oct 22 (Reuters) - Ukraine has offered Russian gas giant Gazprom (GAZP.MM) a 50% tariff discount for an additional gas transit to Europe, a Ukrainian president spokesman said. "Ukraine offers it to Gazprom and European gas traders," Sergii Nykyforov said. Oleksiy Danilov, secretary of the security and defence council of Ukraine, told a briefing earlier on Friday that Kyiv was ready to increase its annual gas transit to Europe by 55 billion cubic meters from the current 40 bcm provided by the 5-year contact with Gazprom. He did not reveal details. read more