RTE is the French electricity transmission system operator. It is a public service company responsible for operating, maintaining and developing the high and extra high voltage network. It guarantees the reliability and proper operation of the power network. RTE transports power between electricity suppliers (French and European) and consumers, whether they are electricity distributors (ERDF and the local distribution companies) or industrial consumers directly connected to the transmission system. With 100,000 km of lines between 63,000 and 400,000 volts and 45 cross-border lines, the network operated by RTE is the biggest in Europe. In 2008, RTE posted turnover of €4,221m and currently employs around 8,500 staff.