The bank also posted a third-quarter net loss of €285 million and an operating loss of €475 million.
"In truth, we have not covered ourselves in glory here. In future, we will have to improve," chairman Martin Blessing said in a statement.
The international financial crisis cost the bank €1.1 billion in losses from market operations, the statement added.
Commerzbank responded to pressure from German authorities for banks to apply for aid under a rescue package that includes up to €80 billion in capital injections and €400 billion in loan guarantees.
The capital infusion will take the form of a "silent participation," which means Berlin will not become an active shareholder in Commerzbank, and the cash will go directly towards boosting the bank's so-called Tier1, or core capital.
That means investors' holdings will not be diluted in Commerzbank, which can also use a capital increase as it is acquiring Dresdner Bank from the insurance group Allianz.
"We have decided to make use of the package because this is good for the bank, its employees and its clients," Blessing said.
"As of today there is not current need for any guarantees. However, they offer additional and attractive refinancing options, in case markets should deteriorate again."
Commerzbank said it had increased loan loss provisions to €628 million from €414 million, a sign the bank expects more turbulence in the future.
Commerzbank shares have lost one third of their stock market value in a month.
In accepting state aid, Commerzbank agreed to forego paying a dividend in 2009 and 2010 and its directors will see their salaries capped at €500,000 per year.
Despite insistent calls from German authorities, the only other private bank to ask for the assistance is property specialist Hypo Real Estate, which asked the state last week to back loans it gets from other banks over the next three years.
Deutsche Bank boss Josef Ackermann told German television late Sunday that the biggest private German bank was "strong" enough to do without state aid.