In a statement, MHI and Siemens said the companies are currently evaluating a potential proposal, with a view to presenting it to Alstom on 16 June.
MHI chief ececutive Shunichi Miyanaga said: "MHI has been invited by Siemens to join forces, and we firmly believe that we can substantially contribute to a partnership solution for Alstom, which will create value for all parties involved, including the country of France".
Siemens CEO Joe Kaeser, said: "I appreciate MHI's commitment to join our efforts and I do look forward to working together with MHI to create a long-term oriented solution for Alstom, MHI and Siemens."
There is a question of how this could affect the wind industry, and notably Alstom's offshore programme surrounding the 6MW Haliade turbine.
If the deal went through it would potentially leave MHI with three offshore wind turbines. Currently it is involved with the V164 8MW, which is a cornerstone of the joint venture with Vestas, and the 7MW SeaAngel that it developed itself.