Scottish Power

(SPI) - Get Report

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.