Dutch grocer Jumbo Group reported an increase in sales for 2013 but its market share came under pressure in a competitive market.

The privately-owned retailer booked a 2% rise in turnover to EUR7.09bn for last year.

However, Jumbo, which runs the namesake and C1000 chains in the Netherlands, said the combined market share of the two banners was 20.1% in 2013, compared to 21.7% in 2012.

The Jumbo chain accounted for a greater proportion of Dutch grocery sales, with its share of the market up from 10.6% in 2012 to 12.6%.

However, the increase was not enough to offset the fall in the market share of C1000, which fell from 11.1% to 7.5%. Jumbo acquired C1000 in 2012 and has been converting stores to its eponymous banner, which explains the decrease in sales at C1000 stores. The increase in Jumbo's share could not make up for the decline at C1000.

Jumbo also reported a 1.8% rise in organic sales at its namesake stores, compared to a market that rose 2%.

Nevertheless, Jumbo said synergies meant its financial results "exceeded expectations". The privately-owned grocer did not disclose profits alongside the sales announcement.

It said its results gave it a "strong foundation" for further growth. The company, which opened its first Jumbo Food Market store in Breda last year, said it would open more outlets, starting in Amsterdam.

The retailer also plans to launch an e-commerce arm this year.