The Surface Transportation Board (STB) has established its timetable to consider an application by Canadian National (NYSE: CNI) to place merger target Kansas City Southern (NYSE: KSU) in a voting trust, a key development in the Canadian railroad's planned $33 billion acquisition. Canadian National last month outbid Canadian Pacific (NYSE: CP) for Kansas City Southern, but the deal must still pass regulatory scrutiny. The railroads expect a drawn-out process to win approval, and Canadian National hopes to use a trust to provide Kansas City Southern shareholders with their compensation prior to the deal winning approval. Image source: Canadian National. Canadian Pacific had already won approval for such a trust structure, but with Canadian National being much larger than either of the other two railroads, there is no guarantee its trust plan will be accepted. The STB rejected Canadian National's initial request, but allowed the railroad to reapply. The STB is allowing public comments on the proposal through June 28, and granted Canadian National until July 6 to respond to comments. Canadian National issued a statement saying, "we are happy with the timetable that the STB has set for reviewing our voting trust," and that it is confident that its voting trust will be approved. Canadian National has argued that the Canadian Pacific trust approval should be a precedent that allows it to proceed as planned, but the U.S. Department of Justice has already weighed in, calling the trust a "mockery" of STB regulatory authority. The STB is likely to seriously consider comments from shippers and other railroad customers in making its decision. It is wrong to conclude that if Canadian National's voting trust isn't approved it is unlikely to eventually win merger approval. However, the STB's decision on the trust and comments that come in over the next 20 days should provide insight into how big a challenge the railroad faces as it tries to buy Kansas City Southern. 10 stocks we like better than Canadian National RailwayWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Canadian National Railway wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 7, 2021 Lou Whiteman has no position in any of the stocks mentioned. The Motley Fool recommends Canadian National Railway. The Motley Fool has a disclosure policy.Source