Embodiments of the present invention provide a method of forming a component comprising: providing a sleeve member formed from a metal matrix composite material; and casting a cast portion of the component whereby at least a portion of the cast portion is provided within the sleeve member. Embodiments of the invention have the advantage that a component of increased stiffness may be fabricated compared with a cast component not comprising the sleeve member. The component may be formed to be of greater stiffness and reduced weight compared with a component of comparable strength and stiffness formed from a material such as steel.
