A process for manufacture of a dendritic polyether comprising a core, derived from a compound having two or more hydroxyl groups, and at least one branching generation being built up from at least one hydroxyoxetane having one oxetane group and at least one hydroxyl group is disclosed. The process comprises ring opening addition to said core and ring opening polymerization of said hydroxyoxetane. A mixture of the core compound and at least one cationic initiator is prepared and said hydroxyoxetane is fed to said mixture at a rate resulting in and/or maintaining a reaction temperature below onset at thermal degradation and in an amount resulting in at least one branching generation. The initiator is present in an amount of 0.1 0.5% by weight calculated on said core and said oxetane, preferably in an amount giving a ratio hydroxyl groups to initiator of between 1:0.01 and 1:0.05. Yielded dendritic polyether is sebsequently neutralised by addition of at least one alkaline compound and optionally purified.