PARIS, Jan 7 (Reuters) - France's power and gas unions said on Thursday they will call for strikes at French power groups Engie and other gas companies on Jan. 14 and at EDF on Jan. 19 if reorganization plans are not withdrawn by next Wednesday.

The Jan. 19 strike would be the fourth day of action since Dec. 10 at EDF over the so-called Hercules restructuring plan, and French union CGT has signaled that it is considering other possible actions if the plans are not repealed.

Unions fear the reorganization of state-owned EDF, which is the subject of negotiations between Paris and the European Union, would pave the way for its dismantling and privatization.

The CGT is also protesting against Engie's review of its activities, in which the group is considering a spin-off of some of its client solutions business.

The unions' strike call also relates to smaller power supplier Gazel Energie, which is planning job cuts, and the 2020 environmental legislation that will gradually phase out the use of natural gas in new single-family homes starting in June.

Unions had already issued a joint call for strike action at EDF on Jan. 19 over the planned reforms. (Reporting by Forrest Crellin, additional reporting by Benjamin Mallet; Editing by Gus Trompiz, Mark Potter and Alexander Smith)