BUZZ-Tullow Oil: Nomura resumes with "reduce" rating

** Tullow Oil down 3.6 pct, top FTSE midcap loser after Nomura resumes coverage with "reduce" rating, PTof 200p

** Fall has wiped out stock's gains since late July, whenstock closed at a 10-yr low

** Nomura expects financial leverage to rise, saysprobability of M&A lower than market suspects, and adds thatthere is a continued downside to its valuation

** Rival Premier Oil also down 3.4 pct,third-largest midcap loser, slipping to levels last seen inMarch

** Nomura resumes coverage of Premier at "neutral", PT of140p

** Analysts highlight risks at Premier's Solan project, aswell 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 pctas it goes ex-dividend (venkateshasoumithri.mamidipudi.thomsonreuters.com@reuters.net)