The European Southern Observatory (ESO) said Thursday it would go ahead with construction of the world's most powerful land-based telescope, a behemoth designed to locate planets in other solar systems.

Building work on the European Extremely Large Telescope (E-ELT) has been authorised by ESO's governing body after funding pledges exceeded 90 percent of the roughly one-billion-euro ($1.25-billion) cost, the organisation said.

The E-ELT will be a 39-metre (1,535-inch) -aperture optical and infrared telescope sited on Cerro Armazones in Chile's Atacama desert, one of the most arid places in the world.

It will be located 20 kilometres (12 miles) from ESO's highly successful Very Large Telescope (VLT) on Cerro Paranal.

Intended to start operations 10 years from now, the E-ELT "will be the world's largest 'eye on the sky'," ESO said in a press release.

"It will enable tremendous scientific discoveries in the fields of exoplanets, the stellar composition of nearby galaxies and the deep Universe," it said.

ESO's governing council approved the E-ELT in June 2012 but attached conditions to launching major work in order to ensure budget discipline.

It said contracts with a value larger than two million euros could only be awarded once the total cost of the telescope -- 1.083 billion euros at 2012 prices -- was funded to a 90-percent level.

An exception was made for ground-clearing work, which began with a ceremony in June this year.

Poland's accession to the ESO means that current funding commitments to the E-ELT have now exceeded the 90-percent threshold, the 15-member organisation said.