The EC said that the recoveries relate to irregularities communicated by the Member States in the period prior to 1 January 1999.
The decision is seen as vital in order to preserve the credibility of the EC's procedures of scrutiny.
"The commission is serious about not tolerating irregular spending of the EU taxpayer's money," said vice-president Siim Kallas, commissioner in charge of administrative affairs, audit and anti-fraud.
"We have sound systems in place to detect such cases, and when one is discovered it will be followed up, even if this may take some time."
Under this decision, funds will be recovered from Italy, Germany, Spain, France, and the United Kingdom. The corrections relate to irregularly paid amounts that should have been recovered by the Member States concerned.
Some €310.8 million will be charged to Italy, €2.4 million to Spain, €2.0 million to the United Kingdom, €1.3 million France and €0.6 million to Germany.
The CAP has come under close scrutiny of late. The disclosure that the European Commission spent nearly €5bn more on agriculture in 2005 than it did in 2004, according to the 'Allocation of 2005 EU expenditure by Member State', has angered some who see the CAP as a monumental waste of money.
Furthermore, over 90 per cent - €44.7 billion - of the EU's agriculture spending went to 'old' member states. In fact, every fifth euro in agricultural expenditure went to France in 2005, with 20.7 per cent. France is followed by Germany (13.5 per cent), Spain (13.3 per cent) and Italy (11.4 per cent).
Such figures suggest that the huge agricultural subsidies the EU has become infamous for remain rigidly in place, with little possibility of reduction. The Common Agricultural Policy still makes up the biggest share of EU legislation. But EC enterprise and industry commissioner Gunter Verheugen said the EC recognised the need for change, and insisted that the CAP has always been capable of modernising.
"Our objective is to eliminate excessive bureaucracy in the Common Agricultural Policy," he said. " We are striving to have modern and simple European legislation and we will only achieve this if the Common Agricultural Policy is also on board."
Verheugen's statement came during the two-day conference in Brussels this week on simplifying the Common Agricultural Policy.
"The Common Agricultural Policy (CAP) has a reputation for complexity," said Mariann Fischer Boel, Commissioner for Agriculture and Rural Development. "That is why it is one of my major priorities to simplify it."
The EC said that the money was being recovered because of inadequate recovery procedures in the Member States concerned. National authorities are responsible for paying out, checking expenditure, and for the recovery of unduly paid amounts under the Common Agricultural Policy (CAP).
The Commission is required to ensure that Member States recover irregularly paid amounts.
"We have been working very hard to ensure the best possible control over farm spending," said Boel.
"This latest decision is the result of painstaking work in cases where we are not satisfied with the way Member States have recovered incorrectly spent money. I think this sends a clear signal of how serious we are."