Reserve currency economy, the German Deutsche Mark gained the status of the second most important reserve currency after the US dollar. When the euro was introduced on 1 January 1999, replacing the Mark, French franc and ten other European currencies, it inherited the status of a major reserve currency from the Mark. Since then, its contribution to official reserves has risen continually as banks seek to diversify their reserves, and trade in the eurozone continues to expand. Former U.S. Federal Reserve Chairman Alan Greenspan said in September 2007 that the euro could replace the U.S. dollar as the world's primary reserve currency.
European Currency Unit accept the European Union legislation to that effect. However, for abundant caution, several foreign jurisdictions adopted legislation to ensure a smooth transition. Of particular importance, the U.S. states of Illinois and New York adopted legislation to ensure a large proportion of international financial contracts recognized the euro as the successor of the ECU. Although the acronym ECU is formed from English words, "écu" is also the name of an ancient French coin. That was one reason that a new name was devised for its successor currency, "euro", which was felt not to favour any single language. The currency's symbol, ₠