The same survey showed that jobs in the retail sector had also suffered a decline (of 2.8 percent) over the same period.
At a national level from January to June this year, retail trade was down 5.4 percent in comparison with the same period in 2011, whilst jobs in the sector fell by 1.1 percent in the first half year.
In June alone, and discounting sales at petrol service stations which fell by 8.1 percent in comparison with the same month in 2011, year on year retail trade was down by 3.9 percent.
Sales of household furnishings and equipment fell last month in Spain by 9.4 percent compared to June 2011, personal items such as clothes, shoes and accessories were down by 5.3% and food down by 0.7%.
Retail sales were down last month across all regions of the country. Only large chain stores managed to increase their sales in comparison with June 2011.