Requests from customers in Austria and Slovakia for Russian natural gas supply via Ukraine rose by 6% on Tuesday compared to Monday, even as Gazprom cut off supply to Austrian energy group OMV this weekend amid a contractual dispute. Nominations from companies in Austria and Slovakia were still 12% below last week’s levels, which was prior to Russian gas giant Gazprom halting supply to OMV. It was not immediately clear which customers in Austria are now buying the gas previously supplied to OMV, Reuters reports, citing figures from transmission…