GE was slated to supply four 6MW turbines each to the Ile de Groix floating project, off Brittany, majority owned by Eolfi and CGN, and the Engie-led Golfe de Lion pilot, off Leucate in the Mediterranean.
However, the company's recent decision to focus on its 12MW Haliade-X turbine, means the company will no longer fulfil the supply deals for the floating sites.
The move follows GE's announcement it had terminated the agreement to supply two fixed foundation projects in France.
"GE offered to supply the turbines, but not to our timetable," said Alain Delsupexhe, chairman of Eolfi, which is close to securing an alternative, more powerful machine, "which makes more economic sense", he added.
Engie has already chosen Senvion's 6.3M152 turbine to replace the Haliade at its Mediterranean site, though said it is "monitoring the situation closely", given Senvion's financial troubles.
Both Eolfi and Engie said the change would not impact the permitting process.
Eolfi expects to receive consent very shortly, while Engie's project has just gone to public enquiry. Both companies still plan to commission their projects by the end of 2021.
First in the water is likely to be EDF Renewables' Provence Grand Large pilot off Fos-sur-Mer in the Mediterranean, which received final consent last week.
Assuming there are no legal challenges, EDF plans to make a final investment decision in the autumn and start construction in 2020. Siemens Gamesa is supplying the three 8MW turbines.
The last of the four pilots awarded in 2016, EolMed's Gruissan, also in the Mediterranean, will go to public enquiry late May and should receive consent in the autumn.