* Polish utilities to have 4.6 gigawatts offline on Saturday
* 858-MW Belchatow unit offline
* Hungarian spot premium remains
PRAGUE, Sept 18 (Reuters) - Forecasts for a fall in renewable production in the region and expectations for lower power plant output boosted Central European day-ahead electricity prices on Thursday, traders said.
On regional exchanges, Czech and Slovak electricity for Friday rose nearly 4 percent to 38.27 euros ($49.31) per megawatt-hour while Hungarian day-ahead shot more than 13 percent higher to 43.36 euros.
Hungarian prompt prices have traded at a regional premium to Czech and Slovak day-ahead, due in part to reduced import capacity during September.
Data from Thomson Reuters Point Carbon showed forecasts for wind generation in Germany dropping more than half to 1.2 gigawatts for Friday, with solar generation ticking about 1.2 GW lower at 4.6 GW.
“There is much less wind and solar tomorrow,” one trader said. “Also, conventional production is becoming dramatically lower over the weekends, which has been supporting prices on Fridays and Saturdays.”
Further along the curve, the Czech Cal ‘15 contract fell 10 cents to 34.05 euros and the Hungarian front year held steady at 43.40 euros in over-the-counter trade.
Around the region, the benchmark German Cal ‘15 contract climbed 5 cents to 34.85 euros on Germany’s EEX exchange in afternoon trade.
Poland’s utilities will have 4.6 gigawatts of power offline for planned maintenance on Saturday, including an 858-MW unit at Belchatow, data from grid operator PSE showed.
Day-ahead on Poland’s POLPX fell to 289.07 zlotys ($88.82) from 347.13 zlotys, remaining high due to a number of unplanned power plant outages, traders said.
Bulgaria is in talks with neighbouring Greece on gas imports, fearing the Ukraine crisis may lead to disruption of supply from Russia, the Bulgarian economy minister said.
Poland, meanwhile, is taking steps towards creating a gas trading and transit hub in Central and Eastern Europe aimed at accomplishing what much of the region has failed to do: shake off almost complete reliance on Russian gas imports.
Oil traded slightly lower below $99 a barrel, pressured by ample supply and concern over the weakening of demand growth in major consumer nations, as well as a rise in the U.S. dollar.
European Union carbon futures rose 1 cent to 6 euros a tonne in afternoon trading. (1 US dollar = 0.7761 euro) (1 US dollar = 3.2545 Polish zloty) (Reporting by Michael Kahn; Editing by Dale Hudson)