A method of fabricating a sector of a turbine engine stator, the method comprising: • making a plurality of single-piece vane fiber blanks; • shaping the fiber blanks in order to obtain single-piece vane fiber preforms; • densifying the vane preforms with a matrix in order to obtain composite material vanes, each comprising fiber reinforcement constituted by the preform and densified by the matrix; characterized in that it comprises: • machining each vane to form a first end and a second end defining between them an airfoil, each first end having dimensions smaller than the dimensions of the airfoil so as to define a shoulder extending around the first end; • making respective slots or notches (1120; 1130) in the first and second ends (112, 113) of the vanes; • making a fiber blank for a first platform and a fiber blank for a second platform; • shaping the fiber blanks to obtain a single-piece fiber preform for the first platform in the form of a circular arc and a single-piece fiber preform for the second platform in the form of a circular arc; • densifying the preforms for the first and second platforms with a matrix in order to obtain first and second platforms (120, 130) made of composite material and in the form of circular arcs comprising fiber reinforcement constituted by the preform and densified by the matrix; • making openings (121, 131) in the first and second platforms (120, 130), the openings of the first platform presenting dimensions greater than the dimensions of the first ends of the vanes, the shoulder extending around each first end presenting dimensions greater than the dimensions of the openings in the first platform; • engaging the second ends of the vanes in the openings of the second platform; • placing a locking element in each slot or notch at the second ends of the vanes; • engaging the first ends of the vanes in the openings of the first platform; and • placing a locking element in each slot or notch at the first ends of the vanes. • making a plurality of single-piece vane fiber blanks; • shaping the fiber blanks in order to obtain single-piece vane fiber preforms; • densifying the vane preforms with a matrix in order to obtain composite material vanes, each comprising fiber reinforcement constituted by the preform and densified by the matrix; • machining each vane to form a first end and a second end defining between them an airfoil, each first end having dimensions smaller than the dimensions of the airfoil so as to define a shoulder extending around the first end; • making respective slots or notches (1120; 1130) in the first and second ends (112, 113) of the vanes; • making a fiber blank for a first platform and a fiber blank for a second platform; • shaping the fiber blanks to obtain a single-piece fiber preform for the first platform in the form of a circular arc and a single-piece fiber preform for the second platform in the form of a circular arc; • densifying the preforms for the first and second platforms with a matrix in order to obtain first and second platforms (120, 130) made of composite material and in the form of circular arcs comprising fiber reinforcement constituted by the preform and densified by the matrix; • making openings (121, 131) in the first and second platforms (120, 130), the openings of the first platform presenting dimensions greater than the dimensions of the first ends of the vanes, the shoulder extending around each first end presenting dimensions greater than the dimensions of the openings in the first platform; • engaging the second ends of the vanes in the openings of the second platform; • placing a locking element in each slot or notch at the second ends of the vanes; • engaging the first ends of the vanes in the openings of the first platform; and • placing a locking element in each slot or notch at the first ends of the vanes.