BRIEF-Akzo Nobel to purchase annuities for US pension obligations

AMSTERDAM, Dec 18 (Reuters) - Akzo Nobel NV : * Says AkzoNobel to purchase annuities for US pension obligations * Annuity purchase is expected to reduce AkzoNobel's US pension obligations by about $655 million * Says to recognise premium payable to MetLife, maintain pre-transaction funded status, have paid $170 million to pension plan * Says annuity purchase will cover around 9,400 US retirees and beneficiaries who retired prior to October 2013 * Says payment administration for pension bene