Scottish Power said on Monday all its operations were performing well and that current year trading was expected to be ahead of expectations, boosting its shares.
The country's fifth biggest energy supplier said good growth at its U.S. based wind farm business PPM Energy and at its wholesale and retail energy arms had raised its hopes.
By 9:49 a.m., its shares were up 3.2 percent at 673p, valuing the group at around 10 billion pounds.
Scottish Power said in May it planned to spend 1.6 billion pounds building up PPM, disappointing some analysts who expected newly appointed Chief Executive Philip Bowman to give some guidance on potential disposal plans.
The firm had just disposed of its main U.S. arm PacifiCorp to refocus on its UK operations, raising its profile as a potential takeover target.
German utility E.ON AG made a bid approach last November but Scottish Power walked away.
The Glasgow based company also said on Monday that the two big price hikes it introduced this year had helped its fortunes.
The recent retail price increases have begun to offset the continuing cost pressures from high wholesale commodity prices as our forward contracts unwind, it said.
The company, which has 5.3 million customers, raised its retail gas and electricity prices twice this year, blaming soaring wholesale costs for the move.
Scottish Power said Energy Retail and Wholesale had continued to benefit from the rolling commodity hedging strategy, further cost efficiencies and a strong performance from our generation fleet, especially the coal fired stations.
It said its Energy Networks business was performing in line with expectations and that it expected no change in the effective tax rate for the year.