BANGKOK: Communist-ruled Laos must deepen reforms to maintain its rapid expansion, the International Monetary Fund (IMF) chief said on Tuesday at the end of a rare visit to one of the world's fastest growing economies. Resource-rich Laos has an annual growth rate of around 7.4 per cent, but gains have not been evenly distributed and poverty remains widespread among its 6.8 million people, the majority of whom work in agriculture. Much of the boom has been driven by huge foreign investment since Communist authorities began a very slight opening up of the economy. In a statement issued after her visit, the Head of IMF Christine Lagarde stressed the need to focus on sustainable growth and bolster the country's fragile economy against shifts in global market.