UPDATE 1-German inflation accelerates in October

(Adds details, analysts, context)

BERLIN, Oct 28 (Reuters) - German consumer prices rose more than expected in October, data showed on Thursday, reflecting growing price pressures as Europe's largest economy grapples with supply shortages and higher energy prices.

Consumer prices, harmonised to make them comparable with inflation data from other European Union countries, rose by 4.6% year-on-year compared with 4.1% in September, the Federal Statistics Office said.

The reading was the highest rate recorded since January 1997, when the EU-harmonised series began.

Energy and food prices rose fastest, the data showed, and Alexander Krueger of Bankhaus Lampe KG wrote in a note to clients that a reading of more than 5% next month was possible.

Inflation has surged this year on one-off factors from tax hikes to supply bottlenecks and commodity price rises, fuelling a debate about the need for exceptionally loose monetary policy.

The figures will be seized upon by investors who doubt the European Central Bank's narrative that high inflation is temporary to challenge its decision on Thursday to keep buying bonds to pin borrowing costs near record lows.

Fritzi Koehler-Geibpersist of KfW bank said in a note that should supply bottlenecks "persist well into 2022, this is likely to have a negative impact on economic growth and will also be felt in consumers' wallets."

High energy prices over winter could push inflation toward 5% this year, she said, predicting that inflation would gradually fall to below 2% in the middle of 2022. (Reporting by Joseph Nasr Editing by Emma Thomasson and Christina Fincher)