** Shares in Fortnox FNOX.ST jump around 37% to an all-time high after a cash offer from EQT EQTAB.ST and First Kraft valuing the Swedish software group at $5.5 billion
** The offer price of SEK 90 ($9.01) per share represents a premium of 38% compared to Fortnox closing price on Friday
** Redeye analyst Fredrik Nilsson says the offer is "fair" though describes it as "on the low side" as the premium to the brokerage's PT of SEK 78 is 15%
** Nilsson adds that especially some international shareholders might be disappointed by the price
** The deal "will remove the greatest success story among listed SaaS in the Nordic market and remove a clear outlier in all peer comparisons," says Nilsson
** Stock hits record high of SEK 89; will see its best day ever if gains hold
($1 = 9.9915 Swedish crowns)
(Reporting by Vera Dvorakova)
((vera.dvorakova@thomsonreuters.com))