Euro zone shares flat ahead of ECB; M&A boosts S&N, Mediaset
* Euro STOXX 50 up 0.2 pct; DAX flat
* Risks seen on the downside following the ECB
* Put/call ratio, volatility index signal cautiousness
* M&A speculation boosts Mediaset, S&N
By Blaise Robinson and Francesco Canepa
PARIS/LONDON, June 5 (Reuters) - Main euro zone equity indexes treaded water on Thursday ahead of a European Central Bank meeting which is expected to yield fresh measures to spur growth.
At its meeting on Thursday, the ECB is expected to impose negative interest rates on its overnight depositors, seeking to prompt banks to lend instead and to prevent the region from slipping into Japan-like deflation, and launch a long-term refinancing operation (LTRO) targeted at businesses.
The euro zone's Euro STOXX index was up by 0.3 percent at 329.87 points at 1111 GMT, while the blue-chip Euro STOXX 50 was up by 0.2 percent at 3,245.54 points and Germany's DAX flat.
After a 9 percent rise in euro zone blue chips since mid-March, a number of traders and fund managers warned of risks of a pull-back in stocks following the ECB announcement and press conference. Continuación...