Sweden's H&M, the world's second-biggest fashion retailer, today reported its steepest sales growth in three years in local-currency terms and said its summer collections had been well received. 

Sales before currency fluctuations were up 8% in the three months from June to August from a year earlier. 

This marked its fifth consecutive quarterly rise, and matched the 8% recorded in the third quarter of 2016.

"Well-received summer collections and increased market share confirm that the H&M group is on the right track with its transformation work," H&M said in a statement. 

Net sales rose more than expected, by 12% to 62.6 billion Swedish crowns ($6.5 billion). Analysts had on average forecast a rise to 61.9 billion crowns, according to data from Refinitiv. 

H&M's shares have soared 51% this year on investor hopes that the group is getting back on track after years of falling profit drops.

The drops were due to slowing sales at its core brand's stores, and investments to adapt to tougher competition and rapidly changing shopping habits. 

But the stock is still trading at a fraction of its 2015 peak, and many analysts have remained cautious, awaiting clear signs of recovery. 

H&M said today that activity levels related to its transformation work had remained high in the third quarter.