MOSCOW, Jan 16 (Reuters) - The Yamal-Europe pipeline, which usually sends Russian gas west into Europe, flowed east from Germany to Poland for a 27th successive day on Sunday, data from German network operator Gascade showed.

Since Dec. 21, the link between Poland and Germany had been operating in reverse mode, putting upward pressure on European gas prices.

The pipeline usually accounts for about one-sixth of Russia's annual gas exports to Europe and Turkey.

On Friday renomination requests, or preliminary bids, to ship gas eastbound from Germany to Poland via the pipeline on Saturday morning were down sharply at hourly volumes of 1.5 million kilowatt hours (kWh/h).

But the actual reverse flows seen on Sunday held close to the volumes of around 7 million kWh/h, the same as on Saturday and earlier in the week, and are expected to remain in reverse until the early hours of Monday, data from the Mallnow metering point on the German-Polish border showed.

It is not clear when the pipeline will revert to westbound flows into Germany. A source close to Gazprom said the company is expected to switch flows at some point this month, as Gazprom has paid for westbound volumes.

Russia has denied accusations from a number of European policymakers that it was withholding gas supplies to pressure German and European authorities to give a green light to the newly-built Nord Stream 2 pipeline.

On Saturday Deputy Prime Minister Alexander Novak repeated that Russia was ready to supply more gas to Europe, but only if there are new long-term contracts - a position Moscow has held since the gas crisis erupted last year. (Reporting by Katya Golubkova Editing by Mark Heinrich)