German econ minister to press on with energy changes

* Wants Berlin to steer building of new power lines

* Says renewable subsidy system must change to rein-in costs

* Propagates relaxing environmental rules

MUNICH, Sept 4 (Reuters) - Germany's economy minister called on Tuesday for the central government to have more power to carry out the planned transformation of the energy network and to cut the generous subsidies given for power generated from renewable sources.

Speaking at an energy conference in Munich, Philipp Roesler said Berlin, the states and municipalities needed to speed up planning for new power transmission lines.

Roesler has an important role within Chancellor Angela Merkel's coalition government, where his Liberal party is the junior partner, in ensuring the success of Germany's ambitious plan to jettison nuclear and fossil fuels for greener energy.

Power lines are needed to transport fast growing energy generated from wind and sun to consumption centres under a master plan to focus more on carbon-free electricity.

If the plan fails to materialise, Germany, Europe's biggest economy, risks falling behind due to rising energy costs and supply uncertainty.

A 2009 plan to build 2,000 kilometres of high voltage power lines had built only 200 km due to bureaucracy, Roesler said.

"The (16) states are responsible to come up with the remainder. I am a great fan of federalism but if we want to get on with more power networks, we need planning at central level," Roesler said.

Certain environmental standards might have to be waived and complaint procedures shortened to handling by just one high court to be able to succeed with the expansion, he said.

In addition to the 2009 plan, grid companies said in May there was a need to build 2,100 km of new direct current lines and 1,700 km of alternating current lines, while 4,000 km of existing power lines needed modernising.

For this plan to succeed, Roesler said a law would be put in place by the end of the year to shorten future new power line construction to four years from 10.

He said he also wanted a major reform of the renewable energy law before the 2013 election, as runaway subsidies were increasing the burden on consumers.

His stance is in stark contrast to that of the Environment Minister Peter Altmaier, who advocates a slower course on the feed-in tariff law, which has made Germany one of the leading green power players in the world.

"We will need to change the renewable energy law, and we will need to do it fast," Roesler said.

Because of this law, German consumers pay above market rates - currently the second-highest power prices in Europe - and the bill for next year is set to rise sharply. (Reporting by Vera Eckert; editing by James Jukwey)