* Iberdrola 9-mth core profit just misses estimates
* Drax says trades in line with expectations for 2009
* Iberdrola down 0.4 percent, Drax up 1.5 percent
By Jonathan Gleave and Victoria Bryan
MADRID/LONDON, Oct 21 (Reuters) - Spanish utility Iberdrola and British peer Drax both struggled to maintain profitability due to weak power prices in Spain and challenging commodity markets.
Core profit at Spain's largest power group in the first nine months of the year just missed estimates as higher operating costs and lower revenue from its deregulated power operations practically wiped out the impact of double-digit revenue growth.
Drax, which runs Britain's largest coal-fired power plant, said in a statement its forward contract position meant it was continuing to trade in line with expectations for this year.
"It will be difficult for Drax to meet expectations as investors are expecting higher margins than the market is allowing right now," said a London-based analyst who declined to be identified.
The analyst added Iberdrola has to sooth investor concerns over whether it can meet its own expectations for 2010.
Iberdrola underperformed its European peers, while Drax outperformed. Iberdrola was down 0.4 percent at 0928 GMT while Drax was up 1.5 percent.
The utilities are the first large utilities to report earnings for the nine months through September. Finland's Fortum reports on Thursday. (With additional reporting by Peter Dinkloh in Frankfurt; Editing by Mike Nesbit)