BUZZ-Miners at top of FTSE as Investec raises PTs

** Shares (Berlin: DI6.BE - news) in mining companies at the top of the FTSE 100 after Investec (LSE: INVP.L - news) raises PTs (Other OTC: PTSH - news)

** Anglo American (LSE: AAL.L - news) , Rio Tinto (LSE: RIO.L - news) , BHP Billiton (NYSE: BBL - news) , Antofagasta (Other OTC: ANFGF - news) up 3.6-6.5 pct

** Investec upgrades BHP Billiton to "hold" from "sell", ups PTs on Anglo American, Antofagasta, Rio Tinto, and Glencore (Xetra: A1JAGV - news)

** Investec says bottom of the market has been tested and found, adds that moves by miners in Q1 such as dividend cuts signal a mild positive bias towards sector

** Analysts add that industry still faces serious challenges

** Rio Tinto sees PT upgrades from JP Morgan, RBC (Other OTC: RBCI - news) , Deutsche Bank following results on April 18

** Stoxx 600 Basic Resources Index up 2.6 pct, best performing sector in Europe, and set for third-straight day of gains (venkateshasoumithri.mamidipudi.thomsonreuters.com@reuters.net)