LONDON, July 11 (Reuters) - European discount retailer Pepco Group on Thursday reported a worse-than-expected 4.3% fall in third-quarter underlying sales, which it said partly reflected supply chain disruptions.

The Warsaw-listed owner of the Pepco, Poundland and Dealz brands, did, however, maintain its profit guidance for the full year.

The group said like-for-like sales in the quarter to June 30 fell 2.7% at the main Pepco business, reflecting the earlier timing of Easter this year, slower selling of old stock that is having to be marked down, and supply chain issues impacting availability of new summer stock.

At Poundland in the UK like-for-like sales fell 6.9%, which the group said reflected challenges related to the introduction of new Pepco-sourced clothing and general merchandise, which are being addressed.

Dealz's like-for-like sales fell 7.3%, also impacted by the transition to Pepco-sourced general merchandise, as well as a highly competitive market.

The group said it still expected 2023/24 underlying earnings before interest, tax, depreciation and amortisation (EBITDA) of about 900 million euros, up from 753 million euros in 2022/23. (Reporting by James Davey; Editing by Himani Sarkar and Kim Coghill)