** British advertising groups S4 Capital SFOR.L up 21% at 23.45p
** Stock among top gainers across the London bourse
** Co expects 2025 net revenue and operational EBITDA to also exceed analysts' estimates of 664 million pounds ($907.16 million) and 75 million pounds, respectively
** Co says full-year 2025 trading better than previously lowered forecast
** In 2025, the stock lost ~38% of its value
($1 = 0.7320 pounds)
(Reporting by Neeshita Beura in Bengaluru)
((Neeshita.Beura@thomsonreuters.com))