Spain's 12-month inflation in October was unchanged from the previous month at 3.5%, preliminary data from the National Statistics Institute (INE) showed on Monday.

Core inflation, which strips out volatile fresh food and energy prices, was 5.2% year-on-year, down from 5.8% in the period through September, the INE data showed.

Spain's European Union-harmonised 12-month inflation was 3.5%, up from 3.3% in September and below the 3.7% expected by analysts polled by Reuters. (Reporting by Tiago Brandao, editing by Inti Landauro)