The shareholders of Poole-headquartered Synergy unanimously voted in favour of the merger. The deal with the Devizes-based organisation would create a group that manages more than 26,000 properties.
In a joint statement, Synergy chief executive Graeme Stanley and Aster Group chief executive Bjorn Howard said: “This is a major step forward in our proposal to merge and we’re delighted Synergy’s shareholders have responded so positively to our plans.
“Synergy and Aster share the same vision and values and customers are at the heart of everything both organisations do.
“Bringing together our joint expertise would be beneficial for everyone – not only would we be ideally placed to deliver better services to customers and build more homes, we believe it will also make us a more attractive partner to central and local government.”
The landlords have a combined 70,000 customers and 1,800 staff between them.