European online consumers this year will spend more than 305 billion euros, approximately $396.5 billion, up 20% from 254 billion euros ($330.2 billion) in 2011, according to a projection from Ecommerce Europe. The multi-nation trade group for online retailers bases the findings on figures from e-commerce associations across Europe and from market research firm GfK.

The steady growth online contrasts with the tepid growth in overall retail sales in the 27-nation European Union. Monthly year-over-year comparisons for 2012 vary from a growth of 3.3% in total retail sales in March to a decline of 1.8% in April, with most months showing growth of 1-2%, according to Eurostat, the EU’s statistical agency.

The United Kingdom, Germany and France continue to generate the largest share of total online sales, about 70% or 213.5 billion euros ($277.5 billion). Year-over-year sales growth in Germany (up 25%) and France (up 20%) remain particularly strong. Sales in the United Kingdom will close the year with online sales up 10%-15%.

Sales in Eastern and Southern Europe, where e-commerce is less mature in terms of the proportion of the population that is shopping online, also are growing strongly, the report says. Ecommerce Europe puts 2012 year-over-year online sales growth for Poland and the Czech Republic in the 25% to 30% range. In Southern Europe, e-retail sales in Italy should grow 19% this year, the report estimates. Dollar figures by country were not immediately available from Ecommerce Europe.

Internet Retailer’s 2012 Top 400 Europe Guide says e-commerce in Poland increased to $5.84 billion from $4.36 billion, or nearly 34% between 2010 and 2011. The 400 Europe Guide says e-commerce in Italy grew to $12.89 billion from $10.33 billion, or about 25% between 2010 and 2011.   

Countries and regions where a greater proportion of consumers regularly shop online, namely the U.K., Scandinavia and France, are now undergoing a shift to mobile commerce, Ecommerce Europe says. 20% of 2012 online purchases in the U.K. will be made via mobile devices, the trade group says, up from 5% in 2011. The mobile commerce share of 2012 online sales in Scandinavia is 8% and 3% in France.

Wijnand Jongen, an Ecommerce Europe board member, says he expects mobile commerce adoption in these countries to trend similarly to that of the United States, where mobile sales for retailers increased 85% from 2011 to 2012, according to the Internet Retailer Mobile 400. “Today 47.6% of all Europeans have a smartphone,” he says. “Here we see a comparable trend. The Scandinavian countries and the United Kingdom have a head start. Other countries will follow soon and fast.”