Eutelsat started the process of selling its Hispasat stake last July when it decided to exercise a put option granted by Abertis in 2008. However, the parties took time to agree on the price and timing of the sale.

After buying out the French group, Abertis could seek a Spanish buyer of Hispasat, which is considered as a strategic asset by the government in Madrid as it offers services for national institutions including the defence ministry.

The Spanish government signalled that it will closely monitor what will happen to Hispasat if Abertis is bought by Atlantia. Italian group Atlantia has made a 16.3 billion euro bid for Abertis which also operates toll roads.

For Eutelsat, a sale fits with its strategy of trying to strengthen its balance sheet by selling non-core assets.

Under Chief Executive Rodolphe Belmer the company has undertaken cost saving measures as it seeks to boost margins, reduce debt and return to revenue growth by the 2018/2019 fiscal year.

"Eutelsat's balance sheet should now close the year comfortably under-levered - before the put, we expect closing leverage of 3.0 times; post the put that goes to 2.8 times," Jefferies analyst Giles Thorne said in a note.

Eutelsat is aiming for a net debt/EBITDA ratio below 3.3 times, according to guidance confirmed by the company earlier in May.

The transaction is expected to close in the second half of 2017, Eutelsat said in a statement.

Eutelsat shares were up 1 percent at 0850 GMT, while Abertis shares were flat.

(Reporting by Alan Charlish and Robert Hetz; editing by Jason Neely and Keith Weir)