The transmission capability of the Finnish transmission network over the main power transfer intersections is restricted by stability limits. Since the deregulation of the electricity markets started in Finland back in 1995, Fingrid as Finnish transmission system owner and operator has actively been improving the transmission capability of the Finnish transmission system in order to minimize the effect of transmission capability limitations on the functioning of the electricity markets. Without building new transmission lines over the main transmission intersections, Fingrid has been able to increase significantly the transmission capability using mainly series compensators and controllable devices but also other structural improvements of transmission network. As the main result of the investments the internal transmission capability from South to North Finland has almost tripled and from North to South Finland has nearly doubled with respect the level of the transmission capability before year 1997. (5 pages)