** Shares of British investment company Downing Renewables & Infrastructure Trust PLC DORE.L up 22.3% at 101.8 pence, highest since June 2023
** Stock is top gainer on FTSE small-cap .FTSC index; on track for a record one-day pct rise, if gains hold
** Bagnall Energy to acquire co for 174.6 million pounds ($235.2 million)
** DORE shareholders to receive 102.6 pence per share
** Bagnall Energy owns 25.4% stake in DORE, according to LSEG data
** Including session gains, DORE up ~33% YTD
($1 = 0.7424 pounds)
(Reporting by Nithyashree R B in Bengaluru)
((NithyashreeRB@thomsonreuters.com))