June 18 (Reuters) -
* Protugal's unlisted company Brisa says it agreed to sell a 30 percent stake in its main motorway concessions unit BCR SGPS for 770 million euros ($878 million).
* To sell the stake in four blocks of shares to a group of unnamed Portuguese-Brazilian investors.
* Millennium bcp Investment Bank and Deutsche Bank London Branch acted as advisers. Source text for Eikon: (here)
$1 = 0.8773 euros Reporting by Andrei Khalip