MILAN, Jan 30 (Reuters) - Clearway Capital Partners has a stake in Italian broadcasting towers company Rai Way , the activist investor said on Tuesday, after a report about its investment sent shares in the Milan-listed company higher.

"We can confirm that Clearway Capital Partners Fund is a shareholder of Rai Way", a spokesperson said in an emailed statement, without disclosing the size of the stake nor the structure of its investment.

Clearway added it was a "long-term investor and always seeks to engage constructively with our portfolio companies for the benefit of long-term shareholders and other key stakeholders".

Shares in Rai Way, which is controlled by state broadcaster RAI, rose as much as 5% after Bloomberg reported Clearway had built a minority stake in Rai Way in a bid to promote a mooted plan to merge with rival EI Towers.

Rai Way declined to comment.

Plans to merge Rai Way and EI Towers to create a national broadcasting towers champion have been on investors' radar for nearly a decade but have failed to materialise so far.

This month, state-owned Rai, which currently owns a 65% stake in Rai Way, announced plans to sell a stake of up to 15% in the TV tower company, drawing criticism from a group of minority investors in Rai Way, a letter sent to the state TV board and seen by Reuters showed.

The group of shareholders argued the stake sale would create less value for Rai Way's investors than a combination with EI Towers.

Under a previous merger blueprint, Rai Way investors would have received a special dividend of around 310-400 million euros ($335-435 million), according to Kepler analyst calculations.

EI Towers is 60%-owned by Italian infrastructure fund F2i, with the remaining 40% held by Italy's top commercial broadcaster MediaForEurope (MFE), which is controlled by the family of late media tycoon and political leader Silvio Berlusconi.

($1 = 0.9222 euros) (Reporting by Elvira Pollina Editing by Keith Weir and Mark Potter)