PARIS (Reuters) - LVMH, the world's biggest luxury company, posted a 1% rise in organic sales in the second quarter on Tuesday, missing analyst estimates, and likely adding to investor jitters about slowing growth in the sector.

Sales at the French group, owner of labels Louis Vuitton, Tiffany & Co. and Hennessy, grew to 20.98 billion euros ($22.8 billion), a 1% rise on an organic basis, which strips out currency effects and acquisitions.

The figure fell below analyst expectations for revenues of 21.6 billion euros, according to an LSEG poll based on six analysts.

The report from luxury sector bellwether LVMH, which is Europe's second-largest listed company, worth around 340 billion euros, comes amid concerns about weak sales of designer fashions in the sector's key market, China.

The group's fashion and leather goods division, which includes the Louis Vuitton and Christian Dior brands and accounts for nearly half of group sales and the bulk of operating profit, grew 1%, slowing slightly from the previous quarter's 2% rise.

"While remaining vigilant in the current context, the group approaches the second half of the year with confidence," said LVMH Chairman and Chief Executive Officer Bernard Arnault in a statement.

($1 = 0.9212 euros)