Swift Holdings, the largest truckload carrier in North America, filed on Thursday with the SEC to raise up to $700 million in an initial public offering. The Phoenix, AZ-based company, which was founded in 1966 and booked $2.6 billion in sales over the last 12 months, was publicly traded from 1991 until a $2.4 billion management buyout in 2007. Morgan Stanley, BofA Merrill Lynch, and Wells Fargo Securities are the lead underwriters on the deal. No pricing terms were disclosed.