** Shares of Havas HAVAS.AS jump 8% after the French advertising company reaffirmed its annual guidance as part of its Q1 statement on Thursday
** It says tariffs have not affected its business since client spending and advertising budgets have not shrunk
** Havas also reports Q1 revenue of 676 million euros ($767.26 million), corresponding to 2.1% organic growth
** The stock is on track for its best day on record since its spin-off last year
($1 = 0.8811 euros)
(Reporting by Leo Marchandon)
((Leo.marchandon@thomsonreuters.com))