1998 - 1953

1998
Occidental becomes the third partner in Equistar. Lyondell acquires ARCO Chemical Company.

1997
Equistar Chemicals, LP is formed as a joint venture between Lyondell and Millennium Chemicals Inc.

1993
LYONDELL-CITGO Refining (LCR) is formed as the Houston Refinery becomes a joint venture with CITGO Petroleum Corporation.

1990
Lyondell acquires low-density polyethylene (LDPE) and polypropylene (PP) businesses from Rexene.

1989
Lyondell is spun off from ARCO, becoming a public company listed on the New York Stock Exchange (Ticker symbol: LYO).

1985
Lyondell Chemical Company is formed from selected chemical and refining assets of Atlantic Richfield Company (ARCO).

1982
Spheripol process, currently the most widely used polyolefins process technology, is first introduced by predecessor company Montedison.

1975
Start-up of the first Hostalen high density polyethylene (HDPE) process plant.

1969
The PO/TBA process, invented by Atlantic Richfield Company. (ARCO), produces propylene oxide with tertiary butyl alcohol (TBA) as the co-product.

1963
Natta and Ziegler are jointly awarded the Nobel Prize in Chemistry for their discoveries in polyolefins technology and catalysts.

1954
LyondellBasell predecessor company scientist Giulio Natta polymerizes the first crystalline polypropylene.

1953
LyondellBasell predecessor company scientist Professor Karl Ziegler discovers the first linear polyethylene (PE) chain.