UPDATE 1-Aeterna Zentaris narrows quarterly loss

*Share loss $0.24 vs consensus $0.22

*Revenue falls 20 pct to $8.4 mln

*R&D costs $12.1 mln (In U.S. dollars)

TORONTO, Aug 11 (Reuters) - Biopharmaceutical company Aeterna Zentaris (AEZ.TO) reported a smaller second-quarter loss on Tuesday, due in part to lower expenses.

The loss at the Quebec City-based company narrowed to $13.1 million, or 24 cents a share, from $20.6 million, or 39 cents a share, a year earlier.

This was due mainly to lower research and development expenses. During the quarter, the company said, it spent $12.1 million, down from $17.3 million a year earlier.

However, the company said revenue dropped 20 percent to $8.4 million due to lower royalty revenue and foreign exchange fluctuations.

Analysts on average were expecting a loss of 22 cents a share and revenue of $6.3 million, according to Reuters Estimates. ($1=$1.10 Canadian) (Reporting by Scott Anderson; Editing by Lisa Von Ahn)