STRESA, Italy, May 24 (Reuters) -

Italy has approved a decree enabling state brodcaster RAI to sell a stake in its tower unit RaiWay, as long as the disposal is compatible with a tie-up of RaiWay with rival EI Towers, a government source told Reuters.

The decree states that RAI, which currently owns 65% of Milan-listed RaiWay, must keep a stake of at least 30% in its tower business, a copy of the document seen by Reuters showed.

Explored for years, a combination between RaiWay and EI Towers would create a national broadcasting towers champion worth more than 2 billion euros ($2 billion). ($1 = 0.9244 euros) (Reporting by Giuseppe Fonte; Writing by Elvira Pollina; Editing by Valentina Za)