MOSCOW, Jan 27 (Reuters) - Gas flows from Germany to Poland via the Yamal-Europe pipeline, which usually sends Russian gas westward into Europe, fell on Thursday morning, data from German network operator Gascade showed.

The pipeline, which usually accounts for about a sixth of Russia's annual gas exports to Europe and Turkey, has been operating in reverse mode since Dec. 21, putting upward pressure on European gas prices.

Eastbound flows on Thursday were at 7.1 million kWh/h, down about 9 million kWh/h over the previous 24 hours, data from the Mallnow metering point on the German-Polish border showed. Flows are expected to remain around this level until the early hours of Friday.

European benchmark gas prices jumped to a record 184.95 euros per megawatt hour (MWh) on Dec. 21 when the Yamal system reversed flow.

Those high prices have discouraged the buying of spot volumes from Russia, with buyers instead tapping stored gas in Europe, where storage levels have fallen below their five-year average.

Capacity nominations for supply to Slovakia from Ukraine via the Velke Kapusany border point, another major route for Russian gas deliveries to Europe, eased on Thursday after rising the previous day to their highest point this year.

Nominations were seen at 448,968 MWh, down from more than 600,000 MWh on Wednesday but around levels recorded earlier this week.

(Reporting by Katya Golubkova Additional reporting by Jason Hovet in Prague Editing by David Goodman )