ROTTERDAM, Netherlands, Dec. 6, 2010 /PRNewswire/ -- LyondellBasell (NYSE: LYB) today announced that the automatic conversion provision has been triggered for its Class B common stock to convert to Class A common stock.  Each holder of Class B shares as of the close of business on Dec. 6 will automatically receive Class A shares on a one-for-one basis, with no action required by shareholders, effective Dec. 7.

The conversion is pursuant to the terms of the Class B common stock, which provided that Class B would convert to Class A common stock once the shares traded above $21.22 for at least 45 trading days within a period of 60 trading days, and closed above the threshold on both the first and last days of the period.

All LyondellBasell common stock will trade on the New York Stock Exchange under the 'LYB' symbol following the conversion.  LyondellBasell currently has approximately 566 million ordinary shares outstanding.

LyondellBasell (NYSE: LYB) is one of the world's largest plastics, chemical and refining companies.  The company manufactures products at 59 sites in 18 countries. LyondellBasell products and technologies are used to make items that improve the quality of life for people around the world including packaging, electronics, automotive components, home furnishings, construction materials and biofuels. More information about LyondellBasell can be found at www.lyondellbasell.com.

SOURCE LyondellBasell Industries