* ICE extends suspension for second time in two days
* Most exchanges have halted spot trade until further notice
(Adds detail, more exchanges)
LONDON, Jan 27 (Reuters) - ICE Futures Europe has extended the suspension of its spot emissions contracts for another week to February 7, it said in a note on Thursday.
This is the second time in two days the bourse has prolonged the freeze.
"The suspension of trading in the (spot) contracts is extended and trading will recommence no sooner than open of business on Monday 7 February 2011, subject to further notice," said the note sent to members.
"The issues (...) remain under investigation and are continuing to be monitored by the exchange and clearing house."
ICE Futures Europe, which operates the largest European emissions exchange, had said on Wednesday it planned to reopen for spot carbon trade on Feb. 1, following a spot trade freeze in the EU's emissions trading scheme.
Most carbon exchanges suspended spot trading last Thursday when the EU Commission imposed a week-long freeze after a potentially concerted theft by cyber criminals of emissions permits worth up to 30 million euros ($41 million).
The EU commission said this week it would only reactivate member states' carbon registries when they have met minimum security requirements and it would give the market 24 hours' notice when it did so.
Some registries have already said they would delay restarting for at least a week.
EXCHANGES
France's BlueNext is also still closed for spot trade.
BlueNext spokesman Keiron Allen could not give a definite day for reopening.
"We remain as we said on Wednesday: we'll reopen the market when we've filtered out the permits in question," he said.
Dutch bourse Climex said it will be closed until further notice.
"We are looking at the situation from day to day since important pieces of information still remain unclear," said Climex spokeswoman Sascha Bloemhoff.
Nasdaq OMX Commodities has suspended spot carbon trade until further notice.
Analyst Emmanuel Fages at Societe Generale/orbeo estimated on Wednesday that lost transactions could amount to 350 million euros ($479.7 million) if the suspension lasted until Feb. 1.
Meanwhile, Czech power group CEZ said on Thursday it had detected two unauthorised transfers of its emissions permits, totalling 700,000, in a cyber attack on the Czech registry last week.
Czech registry OTE has published the full list of missing permits on: http://www.ote-cr.cz/o-spolecnosti/files-novinky/blocks_CZ_20110118_public.pdf (Additional reporting by Gerard Wynn; editing by James Jukwey)