The following companies had unusual price changes in Argentine trading. Stock symbols are in parentheses, and share prices are as of the close in Buenos Aires. The Merval index surged 3.6 percent to 2,351.53.

Metrogas SA (METR) jumped 7.7 percent to 0.56 peso for the largest gain in more than three weeks. The Argentine natural gas distributor reached an agreement with bondholders to restructure its debt, according to a statement posted yesterday on the website of the Buenos Aires exchange.

Siderar SAIC (ERAR) rose 3 percent to 1.70 pesos. The country’s largest steel producer climbed in line with base metal prices and global stock markets, Guillermo Maresco, a trader at Buenos Aires-based brokerage Nacion Bursatil, said in a phone interview.

Tenaris SA (TEN) advanced 6 percent to 115 pesos, its highest closing price in almost four years. The world’s largest producer of seamless steel tubes used in the oil industry had its recommendation increased to the equivalent of buy from neutral at Paris-based Exane Finance.

To contact the reporter on this story: Eduardo Thomson in Santiago at ethomson1@bloomberg.net

To contact the editor responsible for this story: David Papadopoulos at papadopoulos@bloomberg.net