** Tesco hits 2.5-wk highs following weekend pressreports that a bidding war could be in store for Dunnhumby, thecustomer data specialist behind its Clubcard loyalty scheme
** Consumer research giant Nielsen is poised toenter the 2 bln pound auction for Dunnhumby, the Sunday Timesreported
** Race for Dunnhumby includes advertising group WPP
** Dunnhumby put up for sale as part of a drive by Tesco'snew boss Dave Lewis to slash costs & sell assets to mend thegroup's finances (RM: tricia.wright1.thomsonreuters.com@reuters.net)