Howard L. Morgan in 2012.: LONDON — During his long career, Howard L. Morgan has been an early executive at Renaissance Technologies, the giant hedge fund, and a co-founder of First Round Capital, the venture capital firm. His next role: joining the venture capital fund co-led by Eduardo Saverin, one of the co-founders of Facebook. Mr. Saverin’s venture capital firm, B Capital Group, plans to announce as soon as Monday that it has hired Mr. Morgan as its chairman.