More than 99% of shareholders approved the sale at a general meeting on Monday (25 February), with the deal set to complete on 20 March.
It comes after the £1.14bn sale of Emap's consumer and radio arms to H Bauer in early December 2007.
GMG and Apax, who printweek.com tipped as likely bidders in August last year, bought the division through acquisition vehicle Eden Bidco Worldwide, having reached agreement on terms with Emap's board on 21 December 2007.
Apax is also rumoured to be in the frame for New Scientist publisher Reed Business Information, which was put up for divestment last week.
Emap's 1,500-staff B2B arm's titles include Retail Week, Construction News and Drapers, all produced at PrintWeek's printer Wyndeham Heron.
Emap's share price rose 4.5p to £9.25 on the news, up 0.49%.
Emap shareholders greenlight 1bn B2B sale to Guardian and Apax
Emap's shareholders have approved the 1bn sale of its business-to-business division to a joint venture of Guardian Media Group (GMG) and private equity house Apax Partners.
