** Oil & gas exploration co Chariot Oil & Gas up18.5%, among top risers on FTSE AIM index and at anear-3mth high after co targets drilling of three wells withinnext two years
** Says has no debt as at June 30, $29 mln cash at hand
** Peer explorer Parkmead Group up 12.7%
** Parkmead ups stake in Perth & Dolphin oil fields in UKCentral North Sea (Reuters Messaging: rahul.b.thomsonreuters.com@reuters.net)