BERLIN - German Chancellor Angela Merkel said on Tuesday her government may invest "another few billion" euros in a new stimulus package early next year to help overcome the economic crisis.

"We will take action again in January - another few billion could come together," she told a conference of business leaders in the western city of Mannheim, Dow Jones Newswires reported.

But she warned that state aid alone could only "help in a limited way" to end the recession and ruled out a voucher plan for consumers which has been the subject of speculation in the German press.

Merkel said the fresh investment could go toward infrastructure improvements including roads, broadband communications networks and renovation of schools, as well as subsidies for temporary jobs.

The government is to decide in January whether to proceed with a new stimulus package to follow the 31 billion euros ($61.67 billion) already earmarked to fight the financial crisis and economic downturn.

The chancellor has recently come under fire for what critics describe as a timid approach to kick-starting the economy.

Quoting government sources, press reports have said Berlin is preparing to invest 20 billion to 30 billion euros in a fresh economic stimulus plan that will include public investment and consumer incentives.

A report in the daily Frankfurter Allgemeine Zeitung said on Tuesday that the government fears the German economy could contract by 3.0 per cent or more next year, marking the worst recession in German postwar history.