Export growth slowed for the fifth straight month in July as slowing global demand and a strong yen erode a key driver of the economy, government data showed Wednesday.

The deceleration poses a major risk for the export-driven recovery. With lackluster demand at home, Japan has depended on high-growth countries, particularly China, to fuel its sluggish economy.

That expansion is now waning just as exporters face a new onslaught from the yen, which hit a fresh 15-year high against the dollar this week. It weakened slightly Wednesday amid speculation that monetary authorities might intervene in the currency market for the first time since March 2004 to stem the rise.