May 6 (Reuters) - Dutch postal firm PostNL reported a loss for its first-quarter normalised earnings before interest and taxes that was below market expectations on Monday, citing a mainly labour-related challenging environment.

The company, which delivers parcels and letters across Belgium, the Netherlands and Luxembourg, reported a loss for its normalised operating earnings of 9 million euros ($9.68 million), down from a profit of 7 million euros a year earlier.

Seven analysts polled by the company had forecast a loss for quarterly normalised operating earnings of 2 million euros on average.

($1 = 0.9293 euros) (Reporting by Olivier Cherfan in Gdansk; editing by Christian Schmollinger)