The Bank of France revised its 2016 and 2017 growth forecast down to 1.3 percent, having previously expected growth of 1.4 percent this year and 1.5 percent next year.
It also predicted growth of 1.4 percent in 2018, down from its previous figure of 1.6 percent.
"In 2017 and 2018, the downward revision of our GDP growth projection... is mainly due to the deterioration in the international environment," it said in a statement.
"The projection is thus particularly affected by less favourable foreign demand prospects.., notably as a result of the impact of Brexit on the UK economy and of its dissemination to the euro area economies."
France's national statistics agency Insee in October also cut back its outlook for annual growth this year to 1.3 percent from 1.6 percent.
The European Commission forecasts 1.3-percent growth in GDP in 2016 and 1.4 percent next year, while the OECD is betting on 1.2 percent and 1.3 percent respectively.
Britain voted on June 23 to leave the EU, and Prime Minister Theresa May has promised to trigger the two-year divorce process at the end of March.