Madrid - The Basque separatist organisation ETA has been sending more letters to Basque companies demanding money for not being targeted for attacks, El Pais newspaper reported Saturday.

It said ETA had been demanding between 30,000 and 130,000 euros from companies, warning that failure to pay would mean they faced being targeted.

ETA is known to finance its operations partly by such protection money operations. In the organisation's jargon, the companies are required to pay "revolutionary taxes" or "contributions towards liberating the Basque Country".

Spain's King Juan Carlos recently praised Basque companies which resisted such tactics.

However, when in June ETA last sent a series of such demands, investigating judge Baltasar Garzon ordered the arrest of several prominent company heads suspected of having given money to ETA. (dpa)