Apollo was said to be in the process of informing prospective buyers that Southport, Connecticut-based Principal is available for sale, according to financial sources.
Principal filed a prospectus for an initial public offering on the New York Stock Exchange in April 2014 and has updated the filing seven times since, but has not been able to bring out the IPO.
It has been blocked by an IPO market that is not yet open to most shipping offerings, and likely by its relatively modest size, with only 12 tankers.
