By Subrat Patnaik

(Reuters) - Nike Inc's <NKE.N> quarterly revenue growth and its forecast for future orders missed analysts' estimates, underscoring the sportswear maker's struggle to fend off competition from Adidas and others, especially in its home turf of North America.

Nike's shares, already the third worst performer on the Dow Jones Industrial Average with a 15 percent drop this year through Tuesday, fell another 4.2 percent to $50.85 in extended trading.

While Nike still dominates in North America, its biggest market, analysts have said it is losing ground to Germany's Adidas <ADSGn.DE>, and smaller domestic rivals such as Under Armour Inc <UA.N> are also making inroads.

"You are seeing more people moving towards Adidas," Edward Jones analyst Brian Yarbrough said. He said Adidas was "making a comeback" and some U.S. retailers were giving more shelf space to Nike's competition.

Nike's revenue in the fourth quarter ended May 31 was hurt by a strong dollar that ate into overseas sales. Clearing excess inventory in North America also hurt sales and margins, and is expected to dent the current quarter as well, Nike said.

While Nike noted the volatility in the currency markets after Britain's shock vote to leave the European Union, it maintained its full-year sales growth forecast.

Nike expects revenue to grow in the high single digits for the year ending May 2017. Adidas, by contrast, expects its full-year currency-adjusted sales to grow 10-12 percent, thanks in part to a busy sporting calendar that includes the Rio Olympics and the European soccer championship.


Nike's orders for delivery from June through November in North America, a demand gauge it calls "futures orders", missed expectations, signaling slowing growth.

Its futures orders in the region were up 6 percent at the end of the fourth quarter, while analysts were expecting growth of 9 percent, according to Consensus Metrix.

Slipping demand for its basketball shoes hurt Nike's "futures orders", Yarbrough said. The success of Under Armour's basketball shoes endorsed by NBA star Stephen Curry have eaten into demand for Nike's, endorsed by Michael Jordan and LeBron James among others.

Celebrity and team-endorsed products are big sales drivers for sportswear companies. Adidas has hiked marketing spending, particularly in North America, while Under Armour has benefited from deals with Steph Curry and golfer Jordan Spieth.

Nike could benefit from higher demand for basketball shoes after LeBron James powered the Cleveland Cavaliers to their first NBA championship earlier this month.

Nike's fourth-quarter revenue rose nearly 6 percent to $8.24 billion, while analysts on average had expected revenue of $8.28 billion, according to Thomson Reuters I/B/E/S.

Sales in North America were flat, weighed down by a fall in apparel and equipment sales. Footwear sales inched up 2 percent.

Net income fell 2.2 percent to $846 million. On a per share basis, profit was flat at 49 cents and a penny higher than analysts' estimates.

Nike's gross margins dropped 30 basis points to 45.9 percent as higher average selling prices were more than offset by higher product costs, the inventory clearance and currency rates.

(Reporting by Subrat Patnaik in Bengaluru; Editing by Savio D'Souza)