Nigeria, Niger and Algeria today signed an agreement to build a pipeline that will bring Nigerian gas across the Sahara desert to the European markets, according to dpa. Europe is keen to diversify its supply and reduce its reliance on Russian gas, which has been disrupted by repeated disputes with Ukraine. Nigeria is one of the world's top crude oil exporters, but it also has significant gas reserves. The project is expected to cost around 13 billion and hopes to deliver around 30 billion cubic metres of gas per year to Europe. Total and Royal Dutch Shell have expressed interest in the project, but analysts say Russian giant Gazprom is ahead of the curve. Gazprom signed a cooperation deal with Nigeria's state-owned Nigerian National Petroleum Corporation (NNPC) during a recent visit to Nigeria by President Dmitry Medvedev. Medvedev said Moscow could invest up to 2.5 billion dollars in Nigeria's energy sector as Russia tries to catch up with China in gaining a slice of Africa's natural resources. However, militant groups who have attacked facilities and cut Nigeria's oil production by a third since 2006 have vowed to scupper Gazprom's investment plans and any possible gas pipeline.