** Signet Jewelers' SIG.N shares up 12.42% at $54.30 premarket

** Co posts Q4 sales of $2.35 billion, compared with analysts' expectations of $2.33 billion

** Company earns $6.62 per share on an adjusted basis, beating estimates of $6.25, according to data compiled by LSEG

** Co's Q4 same-store-sales declined 1.1%, smaller than estimates of a decline of 2.03%

** SIG stock had fallen about 40.16% YTD, as of last close

(Reporting by Aamir Sohail in Bengaluru)

((Aamir.Sohail@thomsonreuters.com;))