UPDATE 1-European shares edge lower ahead of Christmas holiday break

Sagarika Jaisinghani

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* Banking stocks among biggest decliners on benchmark index

* Trading volumes thin as holidays approach

* Infrastructure group Atlantia pressures Italian index

* Britain's NMC jumps on independent review of books (Adds comment, details; updates prices)

Dec 23 (Reuters) - European shares dipped slightly on Monday after nearing a record high in the previous session, as investors locked in some of the recent gains in thin trading ahead of the Christmas and Boxing Day holidays later in the week.

The pan-European STOXX 600 index shed 0.1%, with the banking sector among the biggest decliners.

HSBC Holdings Plc fell 1.1%, eyeing its worst session in nearly three weeks, as a report said the bank and JPMorgan had accessed the high-speed audio feed of central bank press conferences that could have potentially given them vital seconds of trading advantage.

An improving outlook on the global economy and optimism around a smoother Brexit had sent European equities to an all-time high last week, with the benchmark index logging its biggest weekly gain in two months.

Investors had more reason to cheer towards the end of the week, with the British parliament approving Prime Minister Boris Johnson's Brexit deal and U.S. President Donald Trump saying Washington and Beijing would sign an initial trade pact "very shortly".

But with the trade deal unlikely to be signed this year, and Johnson's willingness to take a hard line on future Brexit negotiations, analysts said stocks had little reason to move much from current levels.

"Things have had a good run recently and we're now just seeing low volumes, low volatility and a small little profit taking," said David Madden, analyst at CMC Markets.

Trade-sensitive German shares were nearly flat. After choppy trading earlier in the year, the index has gained steadily since September as the outlook around the Sino-U.S. trade war cleared up.

A 4% decline for Italian infrastructure group Atlantia pressured the wider country index.

On Saturday, a report said the Italian government had provisionally approved a document to make it easier to revoke concessions to operate motorways. The decree does not mention Atlantia, but a government source told Reuters that the measures could be applied to it.

Lufthansa dropped 1% after German cabin crew union UFO said arbitration talks with the company had failed and its members could stage strikes any time from now on, barring Dec. 24, 25 and 26.

In a bright spot, NMC, whose shares have nearly halved in value since last week after Muddy Waters criticised the healthcare group's financials, jumped 20% after launching an independent review of its books. (Reporting by Sagarika Jaisinghani in Bengaluru; Editing by Rashmi Aich and Saumyadeb Chakrabarty)