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Scottish Power becomes third UK firm to raise energy prices

LONDON, April 20 (Reuters) - Scottish Power will raise its standard variable domestic gas and electricity prices in Britain by an average of 5.5 percent from June 1, becoming the third firm to announce an increase this month.

The move will affect around a third of homes supplied by Scottish Power (around 960,000), Iberdrola (Amsterdam: ID6.AS - news) -owned Scottish Power said.

"The price change follows rising wholesale energy costs and compulsory non-energy costs, such as delivering low-carbon electricity and upgrading meters," the firm said in a statement.

The move follows similar announcements by Centrica (Frankfurt: A0DK6K - news) -owned British Gas and EDF Energy. (Reporting by Nina Chestney Editing by Hugh Lawson)