Like many countries in Europe, the most important search engine in France is Google by a rather significant margin. Some estimates suggest that Google produces over 80% of all search engine visitors in France.
The French search engine marketing sector is growing very rapidly, but from a much smaller base than say Scandinavia or the UK. One of the factors influencing this is that the French had an electronic telephone directory called 'Minitel' quite some time before the Internet was being used in other countries. This delayed the uptake of the web and French search engines putting France behind other major western countries.
However, the use of the internet in France is taking off very rapidly indeed and it's not a market to be ignored.
The French language imposes certain difficulties and challenges on search engine marketers targeting the French market. One of the main issues is accentuation. There are four significant accents in the French language and yet there is also evidence that French speakers do not consistently use accents when they conduct searches in search engines with many dropping accents altogether.
This would be OK if search engines compensated for this (technically known as normalisation) - however unfortunately this is not often the case. Google for instance normalises the acute accent, but all other accents are not dealt with on an equal basis.
'Stemming' which is used to deliver both singular and plural spellings in response to a particular search engine query is not so prevalent in French as there are fewer stemming systems available for the language.