Bloomberg recently reported that Volkswagen might invest in Ford's AV subsidiary Argo AI as part of a growing partnership between the two automakers. Now, we might know how much that investment will cost VW.

VW plans to invest approximately $1.7 billion in Argo AI, The Wall Street Journal reports, citing sources familiar with the matter. Of that total, $600 million will reportedly go to equity, while the remaining $1.1 billion will be spent on additional research and development, the sources told the WSJ.

The Journal reports that VW and Ford will treat Argo as "the nucleus of an equally held joint venture that could receive additional assets from Volkswagen over time." A previous report says the two value Argo at $4 billion, which would put VW's reported future investment at nearly 50 percent of that sum.

Still, neither automaker is willing to cop to anything just yet. "Our talks with Volkswagen continue," a Ford spokesperson said in a statement. "Discussions have been productive across a number of areas. We'll share updates as details become more firm." VW declined to comment. Perhaps that's because, as the Journal's report notes, a "final deal could still fail to materialize."

Right now, the only part of the VW-Ford tie-up that's been confirmed has nothing to do with self-driving cars. VW and Ford announced at the Detroit Auto Show that the two are partnering on midsize trucks and commercial vans, with Ford building a truck for both OEMs by 2022. There are also rumors that VW may allow Ford to develop electric vehicles on VW's MEB scalable electric-vehicle platform, which will underpin VW's I.D. family of future EVs. Cars are expensive to build on their own, so it makes sense that automakers may team up on occasion to bring products to market.