US company Mondelez International is being investigated by EU competition authorities over concerns it may have blocked cross-border sales of its products in the European Union in breach of competition rules. 

The global confectioner's snack brands include Toblerone, Oreo and Cadbury. 

The case is the latest example of the European Commission's crackdown on companies that impose curbs on sales of products between EU countries as it seeks to spur cross-border sales and boost economic growth. 

EU competition enforcers said the issue was parallel trade of Mondelez's chocolate, biscuits and coffee between EU countries where the company is a key producer in a market worth billions of euros. 

"We are opening a formal investigation to see whether Mondelez, a key producer of these products, might have restricted free competition in the markets concerned by implementing various practices hindering trade flows, ultimately leading to higher prices for consumers," European Competition Commissioner Margrethe Vestager said in a statement.

The Commission said potentially anti-competitive practices include agreements which block traders from selling products in some EU countries and others which increase prices or limit volumes for traders who sell products across the bloc. 

It said the company also imposed restrictions on languages used on packaging and may have refused to supply certain traders aimed at curbing imports into certain markets. 

Mondelez faces fines as much as 10% of its global turnover if found guilty of breaching the bloc's competition rules.

Beer giant Anheuser-Busch InBev was recently convicted of using similar methods by ensuring that cheaper beer from the Netherlands and France could not be sold in Belgium. 

The world's biggest brewery group was fined €200m for the practices, which included changing the design and size of beer cans to make them unavailable for cross-border sales.

In 2019, Mondelez sales reached $25.9 billion worldwide and the company is due to unveil its financial results for 2020 later today. 

Mondelez also owns Philadelphia cream cheese, Tang drink and Tuc crackers.