Аннотация:A theoretical analysis shows that a new type of flute instability is possible in a finite-pressure plasma if the pressure gradient is collinear with respect to the magnetic-field line curvature vector. This instability is an extension of the flute instability with variable pressure to the case of finite beta. In the development of this instability the displacement of the plasma is accompanied not only by disturbance of pressure and electric field but also by disturbance of the longitudinal and transverse components of the magnetic field.