** Shares of Australia's Retail Food Group rise as much as 7% to A$0.076 ** If levels hold, stock set for biggest one-day pct gain since June and hits highest since Aug. 20, when it had issued first 6-week results for the fiscal year ** Fuel and convenience firm United Petroleum Group buying shares in Retail Food, according to a report by The Australian
** Report says Avi Silver, which owns United Petroleum, is increasing stake to almost 20% from the last holding of 12.36%
** Stock has risen 1.4% this year, as of last close
(Reporting by Rishav Chatterjee in Bengaluru) ((mailto:Rishav.Chatterjee@thomsonreuters.com;))