The first return to positive sentiment since March came despite the impact on exporters of a yen hovering near record highs and deepening concerns over the eurozone sovereign debt crisis and a slowdown in the United States.

Large manufacturer sentiment in September rose to two from minus nine in June, the quarterly survey showed, slightly lower than a market forecast of three. The sentiment of medium and small-sized firms remained negative.

The figures represents the percentage of companies saying business conditions are good minus those saying conditions are bad. The survey is taken into account by the BoJ when formulating monetary policy.

The rebound was driven by a large upswing in confidence for Japan's automakers, whose output recovered from heavy disruption caused by the earthquake and tsunami to component networks and power supplies.

Large automakers' sentiment improved from minus 52 in June to 13 in September, the survey showed.

The March disasters devastated entire towns along the northeast coast and left 20,000 people dead or missing while wreaking havoc on Japanese industry.

The nation's biggest firms such as Sony and Toyota were forced to shutter plants and halt production due to shortages in electricity and parts after the disaster disrupted supply chains, sending production and exports tumbling.