Both ARMOUR Residential REIT (NYSE:ARR) and closely related entity JAVELIN Mortgage Investment will soon have a new man in the COO's chair. Both firms announced that Mark Gruber has been named to the position. ARMOUR also filled a board seat by naming Carolyn Downey an independent director. Both appointments are effective September 3.

At the moment, Gruber is the head of portfolio management at both ARMOUR and JAVELIN as well as ARMOUR Residential Management, another affiliated company. Prior to that, he managed a $1.1 billion mortgage portfolio at Penn Mutual. Earlier in his career, he worked at Lockheed Martin as an engineer.

Downey was a managing director at financial services company RBS Greenwich Capital, now a unit of RBS Group, from 1989 to 2007. Previously, she was vice president of fixed-income sales at investment bank Salomon Brothers, these days a part of Citigroup.