March 29 (Reuters) - ** Tour operator Tui’s London-listed shares down 10 pct at 697.6 pounds
** Co has secured additional flight capacity for the holiday season after Boeing’s 737 MAX flights were grounded
** Co currently sees one-off impact on underlying EBITA rebased in 2019 of about EUR 200 mln ($224.58 mln); impact attributable to costs related to replacement of aircraft, higher fuel costs and impact on trading
** Co now sees underlying EBITA rebased for FY 2019 down about 17 pct compared with FY 2018
** If the 737 MAX flight does not resume by mid-July, co will need to extend measures until end of summer season
** Co sees additional one-off impact until 30 Sept, 2019 up to EUR 100 mln
** Aviation regulators around the globe grounded Boeing’s 737 MAX planes after a deadly crash in Ethiopia.
** Stock has fallen 33.1 pct year-to-date compared to a 7.4 pct gain in the FTSE 100 index ($1 = 0.8906 euros) (Reporting by Abinaya Vijayaraghavan in Bengaluru)