Thomaes said four million vacancies could not be filled last year because the 18 million unemployed Europeans did not have the qualifications required to take up the available positions.
"We are facing an unprecedented mismatch of skills and personnel. Unemployment numbers will rise from 18 million to 22 million this year, even though there are four million vacancies that employers cannot fill," he said.
A series of "massive re-skilling programmes" will be required to reorient the workforce to fit employers' requirements, he said.
Thomaes was speaking at a press conference in Brussels ahead of the European Business Summit, which takes place on 26-27 March and will seek to address the ongoing turmoil in the global economy.
He revealed the event itself had been in jeopardy due to the effect of the financial crisis on conference sponsors.
"We have been very nervous over the past six months regarding sponsorship of the event. A lot of other events have been cancelled, so it has not been easy to raise €1 million in sponsorship," he said.
Thomaes said plummeting revenues at major companies from the automotive and financial sectors had cast serious doubt on the viability of the EBS, but the two-day conference will still go ahead as planned.
Also speaking at the press conference, Philippe de Buck, director-general of BusinessEurope, said the EBS would be an opportunity to highlight the importance of staffing, green issues and financing for business.
He acknowledged that business must accept responsibility for the current crisis, but said the free market should emerge as the cornerstone of Europe's commercial future.
"As business representatives, we have to accept that the crisis has come from the private sector, not from regulators or governments. We have to be modest, but the market should still prevail," said de Buck.
While Europe needs government recovery plans to boost banks and support the economy, a market-based economy will be essential in the long term, he added.