BUZZ-Premier Oil: RBC upgrades following results
** Premier Oil (LSE: PMO.L - news) +2.2 pct after company announced FY results
** RBC upgrades stock to "outperform" from "sector perform", cites improving outlook and recent share price weakness
** We would expect continued positive share price reaction as Catcher field ramps-up to plateau production through H1/18 - RBC
** Stock among top gainers on FTSE all-share index
** Of 15 brokerages, four rate the company "buy" or higher, six have "hold" and the remainder are "sell" or lower