They may have struck a deal to transfer control of the old NUMMI manufacturing facility, but as of yet, Toyota and electric-car manufacturer Tesla have no firm deal to produce vehicles together.

The Wall Street Journal says a recent stock filing reveals the companies haven't yet inked a deal that could bring Toyota a new EV built at NUMMI, as has been widely suggested. They do report that Toyota and Tesla engineers have met to discuss potential future product plans.

The former New United Motor Manufacturing, Inc. (NUMMI) manufacturing facility is the only confirmed deal between the companies, in fact. By the terms of that deal, Tesla will pay $42 million for the immense plant in Fremont, Calif., which used to build the Toyota Tacoma and Pontiac Vibe. At the same time, Toyota is investing $50 million in Tesla, to take place after the company files an IPO later this year.

The purchase of the NUMMI plant is expected to close late in the year as well, at a critical juncture in Tesla's plan to begin building the Model S, a new electric sedan. That vehicle will not be ready until 2012, and production of the current Tesla Roadster will end in December of 2011--leaving the company without product to sell while it prepares to launch its new sedan.

Tesla has qualified for $465 million in loans overseen by the Department of Energy, as a part of the 2007 energy bill signed by President George W. Bush to foster the development of electric and other green cars. The purchase price of the plant will come from that loan money, according to the Journal.

While Toyota engages with Tesla, it's still not clear what effect the new Tesla deal will have on the deal with Tesla's other major automotive investor, Daimler AG. Daimler purchased 10 percent of Tesla shares last year, then reduced the investment to 6 percent through a share sale to Abu Dhabi interests.

[Wall Street Journal, subscription required]