The main handling operators in Spain are:
Iberia: is not easy to work as dispatcher, they do an examinations each year and if you pass, you may be on stand-by another year depending of their work load. They hire people as temporary workers, but you can expect to get a steady job in 2 or 3 years.
Ineuropa (INH): part of Acciona group. We always look for people with experience in the sector, specially if is in the same airport. Usually customers agents from the company but is not a must.
Newco: Handling section of Spanair. Always people from inside, as INH.
Trhere are some more, depending of the airport.
Recently Menzies started working in some airports in Spain.
Salary usually vary from 1000€ to 1400€ in a 40 hours week contract, but the companys only want people to cover the peaks, so, in the beginning they only offer 30 hours in the summer keeping the seniority ones with the full time contracts.
See you!