LONDON/FRANKFURT/MILAN, May 2 (Reuters) - U.S. hedge fund Elliott is stepping up its activities in Europe, a Reuters review of data shows, as it sees more opportunities to unlock value for shareholders by pushing through management changes, company break-ups and merger deals. Filings with regulators show that eight of Paul Elliott Singer’s activist fund’s 15 disclosed positions in the first four months of 2018 were in Europe, compared to three out of eight in the same period of 2017. Activist hedge funds rarely disclose reasons behind their strategy.