Fortis Investments, part of the Belgo-Dutch Fortis banking group, has lifted its stake in Haitong Securities from 33% to the legal maximum of 49%, the Financial Times reported. It follows Invesco as only the second foreign partner to lift its stake in a strongly performing fund management joint venture following a loosening of rules in December 2004. Industry experts said Fortis had scored a victory by persuading its partner to stick to the original option agreement. The deal would be likely to put further pressure on foreign rivals, which have been trying to lift their stakes amid disagreement with local partners over valuations. Local partners claim the original option agreements no longer reflect the success of certain businesses.