* About 6 pct of European capacity to be idled or shut
* Many power stations in the red, says CFO
* H1 EBITDA at 5.5 bln eur vs 5.54 bln Rtrs poll
* H1 recurrent net income 1.99 bln eur vs 2.09 bln Rtrs poll
* Shares fall 5.2 percent (Adds CFO comment, details on Gazprom, shares)
FRANKFURT, Aug 14 (Reuters) - Germany's No.2 utility RWE followed peers by announcing cuts in generating capacity, blaming an expansion of renewable energy that has pushed many gas and coal-fired plants into losses.
Germany's utilities are suffering from plunging wholesale power prices, which are down by about a fifth in the year to date, and subsidised renewable energy that takes priority feeding into the grid, thereby reducing the hours that many conventional plants can run.
"Many of our power stations are now in the red," Chief Financial Officer Bernhard Guenther told journalists during a conference call on Wednesday. "This is the greatest crisis our industry has faced for many decades."
RWE said it would take offline 3,100 megawatts (MW) of power plant capacity in Germany and the Netherlands, about 6 percent of its European total of 52,000 MW, and added that it is assessing similar steps for more plants while cancelling sizeable supply deals involving power purchases from other suppliers.
A source told Reuters on Monday that the group was planning to idle or shut down thousands of megawatts of capacity.
On Tuesday larger peer E.ON said it had already shut down or idled about 6,500 MW of capacity and may close or mothball more than the 11,000 MW it had previously put under review.
NO GREAT EXPECTATIONS
Operating profit at RWE's conventional power generation business, accounting for 17 percent of the group's total, was down by 62 percent year on year at 690 million euros ($913 million) in the first half, triggering further savings efforts at its power plant division.
Having recently fallen to a 10-year low, shares in RWE and E.ON have proven to be a challenging investment, with little growth prospects in the foreseeable future.
At 0930 GMT, shares in RWE were 5.2 percent lower at the bottom of Frankfurt's benchmark DAX index, as analysts pointed to slightly lower than expected first-half results and a strong rise in the group's shares a day earlier on the back of good results by peer E.ON.
"You shouldn't have great expectations when it comes to growth. The amount of electricity in Germany shrinks, there is less demand for the product," said Thomas Deser, senior fund manger at Union Investment, which holds 0.55 percent in RWE, according to Thomson Reuters data.
"The company should try to lower costs as much as possible and become a reliable dividend machine," he added.
RWE said recurrent net income rose by 19 percent to 1.99 billion euros in the first half of the year, below the 2.09 billion average forecast in a Reuters poll.
The strong year-on-year rise was mainly because of an arbitration ruling under which Russia's Gazprom had to reimburse RWE for overpayments on gas purchases.
This, RWE said, had boosted first-half operating earnings by 1 billion euros. ($1 = 0.7555 euros) (Additional reporting by Vera Eckert; Editing by Peter Dinkloh and David Goodman)