Four large railroads said they will invest in e-commerce company Arzoon.com to help it build a Web site that will let railroad customers purchase capacity and handle logistics using the Internet. Union Pacific Corp., CSX Corp., Norfolk Southern Corp. and Canadian Pacific Ltd. made undisclosed investments in San Mateo, Calif.-based Arzoon.com. The site is a marketplace of sorts, in that it will focus not just on providing an Internet front-end to its partner businesses, but also on helping customers piece together logistics orders that include multiple carriers. It will compete with Freightwise.com, an online marketplace launched with the backing of Burlington Northern Santa Fe. Logistics considerations are rising in importance in the marketplace world, as buyers and sellers--and middlemen e-markets--realize that efficiently moving products from place to place is as important as the initial transaction. Yesterday, Ariba Inc., Mountain View, Calif., cut a deal with Descartes Systems Group Inc., Waterloo, Ontario, to add logistics capbilities to the Ariba Network.