Paul Perez, United States Attorney for the Middle District of Florida, resigned Tuesday to take a job with Fidelity National Financial, Inc. Appointed in 2002 by Pres. George W. Bush, Perez will officially step down March 30 to become Fidelity’s chief compliance officer.Perez, 52 and a resident of Atlantic Beach, sent his letter of resignation to both Bush and Attorney General Alberto Gonzales.