BUZZ-Tullow Oil: Nomura resumes with "reduce" rating
** Tullow Oil (LSE: TLW.L - news) down 3.6 pct, top FTSE midcap loser after Nomura resumes coverage with "reduce" rating, PT of 200p
** Fall has wiped out stock's gains since late July, when stock closed at a 10-yr low
** Nomura expects financial leverage to rise, says probability of M&A lower than market suspects, and adds that there is a continued downside to its valuation
** Rival Premier Oil also down 3.4 pct, third-largest midcap loser, slipping to levels last seen in March
** Nomura resumes coverage of Premier (NasdaqGS: PINC - news) at "neutral", PT of 140p
** Analysts highlight risks at Premier's Solan project, as well as sensitivity to long-term oil price moves
** Both stocks leading fall in FTSE 350 Oil & Gas Index , which is down 1.4 pct, with BP down 3.2 pct as it goes ex-dividend (venkateshasoumithri.mamidipudi.thomsonreuters.com@reuters.net)