Austria's natural gas supplies from Russian via Ukraine have dropped by about a third, Austrian oil and energy group OMV said on Monday.

"Overnight, the reduction in Russian gas imports increased significantly," OMV said in a statement, adding that the problem was much more serious than previously thought.

The reduction came after Russia cut off gas supplies to Ukraine on Sunday as the two nations failed to resolve a price dispute by a Saturday deadline. Russia is seeking to sharply raise the price of gas but Ukraine has rejected Moscow's demands.

OMV spokeswoman Bettina Gneisz had already announced an 18 percent drop in gas supplies on Sunday evening.

Reports from Hungary and Slovakia, which receive Russian gas pumped through Ukraine before passing it on to Austria, said on late Sunday that there was a noticeable drop.

Despite the increasingly severe gas shortfalls in Austria, the OMV said the gas reserves and domestic production were enough to meet the needs of the population and firms.

OMV Manager Werner Auli said there might be a bottleneck in supplies to large users, but under no circumstances would there be cuts for the private households.

Annual gas consumption in Austria stands at around 8.6 billion cubic meters and 59 percent of it comes from Russia.