* Manufacturers most worried by commodity prices - DIHK
* Currency manipulation must be taken seriously - DIHK
* Commodities prices hovering at two-year highs
(Adds commodities price index)
By Gernot Heller
BERLIN, Oct 26 (Reuters) - German firms are increasingly worried about the rising cost of raw materials and energy, which pose the biggest risk to the economy, the head of the country's chamber of industry and commerce (DIHK) said on Tuesday.
"Rising energy and raw materials prices are the biggest economic risk for companies," DIHK President Hans Heinrich Driftmann told Reuters in an interview.
Driftmann also said leading economies must avoid keeping their currencies weak to give their firms a competitive edge in international markets, even if German firms can cope with the currently strong euro.
Raw materials costs have been rising as countries worldwide race to lock in supplies of resources, with rapidly growing China in particular striking huge investment deals in Africa this year while also benefiting from its own weak currency.
According to the DIHK, some 44 percent of German firms saw rising costs as the biggest risk to their business, though among manufacturers the number rose to 66 percent, Driftmann said.
"It's not just the big increase in prices that are a problem, a lot of companies are worried about having their access to raw materials cut off," he said.
"In view of this, it's imperative we reach European -- or better yet -- international agreements on raw materials with fair rules for all export and import countries," he added.
Germany, which depends on supply of raw materials from abroad to power its export-driven economy, is staging a major congress to address the issue on Tuesday.
The 19-commodity Reuters-Jefferies CRB index, a key benchmark for commodities prices, has been hovering at two-year highs this month.
German Economy Minister Rainer Bruederle criticised China while on a trip there this month for restricting supplies of raw materials, access to which in Africa has also been at the centre of a tug-of-war between western powers and China.
China's trade with Africa is expected to top $100 billion in 2010, a huge leap from $91.1 billion in 2009, according to China's Ministry of Commerce.
Driftmann also lent his voice to the chorus of German policymakers insisting that leading economies must avoid keeping their currencies weak.
"Even if our exporters can cope well with the stronger euro, we can't take lightly attempts by countries to obtain a short-term advantage with a weak currency," he said.
Still, Driftmann said the strength of the German economic upswing, which has surprised many analysts, meant that Europe's largest economy could recover the ground lost in last year's recession and get output back to pre-crisis levels as soon as 2011.
The pick-up -- which this month prompted a group of leading think tanks to forecast the German economy would grow some 3.5 percent this year -- should be used as a springboard for reform of local authorities' finances, Driftmann said.
"We also need to get a real tax reform started that simplifies the system and brings relief, focusing especially on corporate tax and on small and medium-sized firms," he said. (Writing by Dave Graham; Editing by Hugh Lawson)