Michaele Hustedt said there would be amendments to the draft law, which was agreed in August after a long drawn-out debate and scheduled to be presented to parliament on November 16.The initial draft, due to come into force in 2002, said support for CHP plants should end in 2010, but a fresh controversy within the coalition over whether to extend this by up to five years needed settling, Hustedt said.
The limited timeframe did not give any incentives to producers to invest in new CHP plants and in modernisation programmes.
Hustedt also said she still expected the law to be passed by government this year.
CHP uses excess energy from power generation to heat buildings, thereby increasing overall energy efficiency.
CHP plants account for ten percent of total power production in Germany.
Half of all plants are controlled by municipalities, the other half are industrial on-site plants.
Germany's emissions programme aims for a 23 million tonnes annual cut in carbon dioxide emissions by 2010 through CHP production.
Total investment in CHP is expected to total 8.7 billion marks ($4.0 billion), which will be mostly collected from consumers across the supply chain.