Oct 1 (Reuters) - ** The oil and gas producer up as much as 7 pct after saying on Tuesday evening that a review it began in July revealed no further incidents of unauthorised payments
** Top percentage gainer on the FTSE-250 midcap index & biggest one-day percentage rise since August when stock hit lowest point in 2-1/2 years. Chart: link.reuters.com/pur92w
** Company reiterated the assets and operational position of the Company had not been negatively affected
** Westhouse Securities analyst Jamal Orazbayeva says stock will continue to be volatile on speculation, view remains unchanged at 'Neutral'
** Review being conducted by Willkie Farr & Gallagher now expected to conclude in mid-October (firstname.lastname@example.org)