BUZZ-Ophir: Doubts about FLNG prompts CS rating cut
** Oil and gas producer Ophir down 2.4 pct, top loser on FTSE 350 Oil & Gas Index, after Credit Suisse cuts rating on stock to "underperform" from "neutral", PT to 125p from 195p
** CS analysts skeptical of co's stake in its Fortuna floating LNG project; say that FLNG is an unproven concept and that the timeline for the project is ambitious
** Rival Cairn Energy shares down 2 pct as CS initiates coverage with a rating of "underperform" and PT of 185p
** Cairn shares second-largest losers on FTSE 350 Oil & Gas Index; both Cairn and Ophir shares among top FTSE midcap losers (venkateshasoumithri.mamidipudi.thomsonreuters.com@reuters.net)