(Adds details from statement, CFO call with analysts)
PARIS, July 26 (Reuters) - LVMH, the world's biggest luxury group, cautioned on Wednesday that an uncertain economic climate meant its second half results may not match its sterling performance in the first six months of the year.
LVMH reported a 23 percent rise in first-half operating profit, driven by strong demand worldwide for its main Louis Vuitton brand and for its wines and spirits.
The group whose brands also include Dior, Fendi, Hennessy cognac and jeweler Bulgari, said it also faces a more demanding year-ago comparison in the second half.
Chief Financial Officer Jean-Jacques Guiony told a conference call with analysts that Hennessy cognac would see slower growth in sales volumes in the second half of the year due to supply constraints.
"You should expect low to mid-single digit volume growth at Hennessy," he said.
This would compare with 16 percent volume growth for Hennessy in the first half thanks to strong demand in the United States and a rebound in China.
LVMH said first-half profit from recurring operations totalled 3.640 billion euros ($4.23 billion), below a Reuters poll forecast of 3.75 billion euros.
Second quarter like-for-like group sales rose 12 percent, a slight deceleration from 13 percent growth in the first quarter, but beating analysts' estimates for 9.6 percent growth.
LVMH, which like the wider industry has benefited from a recovery in Chinese appetite for luxury goods after an economic slowdown, had cautioned in April that its strong first quarter performance may not be sustainable.
LVMH's fashion and leather division, which accounts for the bulk of its sales and profits and is home to the Louis Vuitton, Fendi and Givenchy brands, had like-for-like revenue growth of 13 percent in the second quarter, against 15 percent in the first. This compared with analysts estimates for 12.2 percent growth.
However, the unit's profit from recurring operations rose 34 percent in the first half to 2.192 billion euros, achieving an operating margin of 31.8 percent of sales, driven by strong growth in Asia, Europe and the U.S.
LVMH's rivals in the luxury industry such as British brand Burberry and French group Hermes have also signaled better demand in mainland China and improving tourist spending in Europe.
($1 = 0.8597 euros) (Reporting by Dominique Vidalon; Editing by Susan Fenton)