LISBON, June 30 (Reuters) - Portuguese consumer prices rose 3.4% year-on-year in June in a significant slowdown from a 4.0% increase the previous month and at a lower pace than in the wider euro zone, flash data released by the National Statistics Institute (INE) showed on Friday.

Core inflation, which strips out volatile food and energy prices, clocked 5.2% year-on-year, down from a reading of 5.4% in May.

The decline in the main inflation rate was driven by a fall in energy prices, which dropped 18.8% from a year ago, following a 15.5% slump in the previous month, while prices of unprocessed food products still rose 8.5%, slightly less than May's 8.9% and way below a peak of over 20% earlier this year.

The government in April exempted more than 40 essential goods, including milk, bread, rice, tomatoes, and some types of meat and fish from value-added tax for six months.

On a monthly basis, Portugal's consumer prices rose 0.2%.

Inflation has been coming down after peaking at 10.1% year-on-year in October 2022, the fastest pace of consumer price rises in more than three decades. (Reporting by Patrícia Vicente Rua and Gdansk newsroom; Editing by Andrei Khalip)