UPDATE 1-H&M shares tumble on surprise quarterly sales drop

* Sales fall in three months to end of November

* Company struggling to adjust to rapid growth of online

* Shares hit lowest point since 2009 (Adds detail, background, shares)

STOCKHOLM, Dec 15 (Reuters) - Fashion retailer H&M said on Friday sales had fallen during the last three months as fewer shoppers visited its stores, sending its shares plummeting and underlining its struggle to adapt to a shift of business online.

Shares in the world's second largest fashion retailer fell 13 percent to their lowest level since 2009.

The Swedish group said sales in the September-November period were far below its own expectations. It plans to speed up efforts to adjust to changes in the market, including closing more H&M stores and opening fewer new ones, and start selling the brand through Chinese online platform Tmall..

"The quarter was weak for the H&M brand's physical stores, which were negatively affected by a continued challenging market situation with reduced footfall to stores due to the ongoing shift in the industry," the company said in a statement.

"In addition, there have been imbalances in parts of the H&M brand's assortment composition," it added, suggesting issues with the product ranges.

H&M has seen inventories pile up over the past two years.

Fourth quarter sales shrank 4 percent year-on-year, or 2 percent in local currencies, to 50.4 billion crowns ($5.97 billion), lagging a mean Reuters poll forecast for a 2 percent increase, or 5 percent in local currencies.

Main rival Inditex, the owner of Zara, has outperformed H&M and others in recent years, helped by a more flexible supply chain that allows it to adapt quicker to demand.

The Spanish company this week reported slower sales growth in the three months through October but said sales growth had gained pace again in November.

A string of analysts have lowered their ratings on the H&M stock recently amid concerns that H&M won't be able, despite rapid online growth, to keep up with newer and nimbler pure-online players such as Zalando and Asos, and that comparable sales declines will extend into 2018. H&M's full quarterly earnings report is due Jan. 31. ($1 = 8.4353 Swedish crowns) (Reporting by Anna Ringstrom; Editing by Johannes Hellstrom and Keith Weir)