Investors in Fortis, the stricken Dutch-Belgian financial group, faced yet more uncertainty on Monday after a former subsidiary now under Dutch government control said it was seeking €362.5m ($504m) in compensation from its erstwhile parent. The claim, already the subject of two sets of legal proceedings, relates to the redemption of securities issued internally to finance the group in the 1990s. The arrangement became highly complex after Fortis was split into three different entities last October.