Fitch Ratings Inc. has affirmed the insurer financial strength rating of Athene Annuity & Life Assurance Co. at BBB+ (Good) and removed it from rating watch negative, with a stable rating outlook, Insurance Networking News reported. Fitch placed Athene on rating watch negative on Dec. 21, 2012, following the company's announcement that Athene Holding Ltd. would be acquiring West Des Moines-based Aviva USA and its subsidiaries, Aviva Life and Annuity Co. and Aviva Life and Annuity Co. of New York from Aviva PLC. Following completion of the acquisition on Oct. 2, Fitch completed a comprehensive review of the Aviva USA business.