ScottishPower, a unit of Spain's Iberdrola, said on Monday its Whitelee wind farm near Glasgow is to be completed ahead of schedule in the next few weeks.

ScottishPower Renewables said all of the 140 turbines at the farm would be ready in the near future, raising its capacity to 322 megawatt -- enough to power more than 180,000 homes. It would be Europe's largest onshore wind farm.

The company began working on the project 10 years ago, with planning consent awarded in 2006. Its first turbines started generating power in January last year. It covers an area of 55 square kilometers (21.2 sq mile), and 970 kilometers of cables have been laid.

ScottishPower has applied to expand the farm by 36 turbines, or to 452 megawatt, the company said.

(Reporting by Nao Nakanishi, Editing by Peter Blackburn)