The architect of Commerzbank's takeover of Dresdner Bank promised no sackings before Christmas yesterday as he outlined how he would orchestrate one of the City's biggest culls.

Martin Blessing, the chief executive of Commerzbank, pledged that Commerzbank staff would not be favoured as he sought to cut about 1,000 London jobs - one in three people - across the two banks' City operations. In presentations to the two workforces yesterday, he said that the move would be fair and transparent.

Earlier, he told The Times that nobody would lose their job before the €10 billion (£8 billion) deal had been completed, probably at the turn of the year. “There will be no redundancies before Christmas, and you don't fire people on Christmas Eve, do you? We are in the process of forming integration teams. We will decide the first management layer [in each division] in the next couple of weeks.”

Decision-making then would cascade down the organisation, Mr Blessing, 45, said. He took the top job at Commerzbank three months ago.

One option might be to use external human resources consultants and to ask staff to apply for jobs.

The redundancy programme will be one of the biggest in recent City history, eclipsing even the 900 jobs being shed at UBS in London. Commerzbank employs about 1,000 people in London, while the Dresnder Kleinwort operation has about 2,000.

Mr Blessing said: “Cutting jobs is not the nicest thing to do. I've had a lot of sleepless nights. You have a responsibility not just to your shareholders but to your workforce.” Staff at Commerzbank and Dresdner would be eligible for a bonus to reward their efforts in the current year, but not everyone would necessarily benefit. “Will there be a bonus pool at both Commerzbank and Dresdner this year? Yes. Will everyone get a bonus? I don't know. That depends on individual performance.”

Dresdner Kleinwort staff are due to be told their bonuses in December and to be paid them in January. Commerzbank staff are told in February and paid in March.

Mr Blessing conceded that there was a risk that the banks would lose key employees and clients amid current uncertainty. Headhunters are already sounding out personnel regarded as rainmakers in the two firms. “I know there's a danger,” he said. “We will do whatever we can to minimise this. Can we keep 100 per cent of the people we'd love to keep? No.”

He emphasised that he was “deeply committed” to retaining investment banking expertise. However, Commerzbank is pulling back from areas such as proprietory trading, UK equities and mergers and acquisitions.

Mr Blessing was open to offers for the unwanted parts of the business, although he was sceptical that there were serious buyers out there. “If they want to, it's not so difficult to reach me. I haven't been called yet. If there's a business out there which wants to buy our assets, we'd be imprudent not to listen. I'm not dogmatic, I'm pragmatic.”

Mr Blessing defended the deal, arguing that the cool investor reception - Commerzbank shares slumped by 10 per cent on Monday after it was announced - was because of uncertainty over the formula for the share exchange with Allianz, the seller. He said that the combination would create benefits, but in the medium term, not the short term. He said that after slimming down in London, there would be opportunities for expansion in equity derivatives, institutional sales and structured products.

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