Syntaxis Capital, a provider of mezzanine financing in Central Europe, has invested EUR11.5 million (approximately US$15.6 million) in Poland-based online travel agency eSKY. The company provides travel services to individuals, focusing on airline ticket sales for both traditional and low-cost carrier flights. eSKY intends to use the funds to support and accelerate its geographical expansion and pursue add-on acquisitions in Europe and Latin America.