** Shares of British software firm Sopheon SPHN.L jump
88.8% to 925 pence, set for best day ever
** Co announces possible offer of 10 pounds per share from
U.S.-based software firm Wellspring, which values it at 114.9
mln pounds ($139.66 mln)
** SPHN says it has "reached an agreement in principle on
the key terms of the possible cash offer" and that discussions
are advanced
** SPHN intends to recommend shareholders to vote in favour
of deal, if firm offer made
** Stock up over 55% YTD
($1 = 0.8227 pounds)
(Reporting by Eva Mathews in Bengaluru)
((Eva.Mathews@thomsonreuters.com;))