(Reuters) - Staples Inc <SPLS.O>, the largest U.S. office supply chain, reported lower-than-expected quarterly revenue, weighed down by weak sales in Europe and Australia.

The company posted a net loss of $596.3 million, or 89 cents per share, for the third quarter, compared with a profit of $326.4 million, or 47 cents per share, a year earlier.

Excluding items, the company earned 46 cents per share.

Sales fell about 2 percent to $6.35 billion.

Analysts on average were looking for a profit of 45 cents per share on revenue of $6.45 billion, according to Thomson Reuters I/B/E/S.

Office supply chains are a good gauge of economic health because demand for their products is closely tied to white-collar employment rates.

Staples shares, which have fallen 21 percent this year, closed at $11.25 on the Nasdaq on Tuesday. (Reporting by Ranjita Ganesan and Chris Peters in Bangalore; Editing by Don Sebastian)