UAE firms Dana Gas and Crescent Petroleum said it had signed a memorandum of understanding with Yemen to build a "gas city" in the Arab state facing dire economic straits and a revolt. "(Gascities) has reached an agreement with the Yemeni government to investigate the development of its proprietary gas city concept within Yemen," a statement said, referring to the Gascities joint venture between Dana Gas and its parent company Crescent Petroleum. "Gas cities" are large, gas-fed industrial complexes housing petrochemical and heavy manufacturing plants. Dana Gas and Crescent plan to build at least four in the Middle East and North Africa, including in Egypt. Gascities says the project could bring some $15 - 20 billion of investment over 25 - 30 years, doubling Yemen's level of foreign direct investment. The city could generate some 15,000 direct jobs and 75,000 jobs indirectly. Gascities chairman Badr Jafar said in the statement that phase one of the project would establish a viable feedstock profile and choose a location for the gas-based industrial city. "At this point it is envisioned that Yemen Gas City will comprise a chemistry park containing methanol and fertiliser factories, a utilities hub that will make the project completely self-sufficient for all utilities ...," Jafar said. Yemen is hoping that exports of superchilled gas will offset the impact of falling oil revenues on its fragile economy. At the end of 2008, Yemen held 17.3 trillion cubic feet of proven natural gas reserves, according to the BP Statistical Review.