Swift Transportation Company Inc. has hired Principal Financial Group Inc. to run defined contribution and nonqualified retirement plans that have about 18,000 participants.

Swift, Phoenix, a trucking company, serves 40 terminals in 26 states and Mexico.

Principal, Des Moines, Iowa, will be offering Swift plan participants toll-free telephone access to retirement specialists; on-site investment education and retirement planning seminars; online account information; access to asset-allocation tools; rollover assistance; and a quarterly retirement planning magazine.

Compass Financial Partners L.L.C., Greensboro, N.C., is Swift’s retirement programs advisor.