International Monetary Fund chief Christine Lagarde called for financial "transparency" among multinational companies to counter tax avoidance schemes in which less-developed countries suffer the most. Her comments came amid the continuing fallout from the "Panama Papers" leak, which has brought to light techniques used by some large companies to reduce taxes by reporting profits in low-tax jurisdictions. "It should be a major concern," Lagarde said during a panel at the spring meetings of the IMF and the World Bank. "What could be done to address these issues is transparency" -- on loopholes, business activities, profit allocation and locations of subsidiaries, she said. Lagarde noted there was momentum to change existing financial practices and systems, "but we need to sustain that momentum and it needs to be followed up by delivery." "We're certainly keen at the IMF to propose some changes in that respect together with other international institutions," she said. According to a recent report from anti-poverty group Oxfam, corporate giants such as Apple and General Electric stashed nearly USD 1.4 trillion in offshore tax havens between 2008 and 2014. Lagarde said developing countries are the main victims of these legal financial techniques that deprive them of vital funds. "They're the ones who rely the most on corporate income tax ... and they're the ones who lose out to the great creativity and inventiveness of the multinationals," she said.