Scottish Power ( SPI) has agreed to be acquired for more than $22 billion by Iberdrola SA, the second-biggest power utility in Spain.

Scottish Power is the fifth-largest energy company in the U.K. In addition to its United Kingdom operations, it also runs power-generating and gas facilities in the U.S.

The merger is the latest in a consolidating European power market. Germany's E.ON ( EON) wants to buy Spain's Endesa ( ELE), and France's Suez ( SZE) and Gaz de France are planning to join up.

Last year, Scottish Power rejected a takeover offer from E.ON.