A chunk of LyondellBasell (LYB -0.30%) shares are hitting the market. Major shareholders are teaming up to sell 15 million of the company's shares in an underwritten public offering priced at $74.10 per share. Those investors have been identified by the company as affiliates of Apollo Global Management (APO) subsidiary Apollo Management Holdings.

In the press release announcing the news, LyondellBasell stressed that it will receive no part of the issue's estimated net proceeds of $1.1 billion, as it is not a selling party.

Barclays unit Barclays Capital is the underwriter of the offering, which is expected to close on Wednesday.

At the moment, LyondellBasell has a little more than 567 million shares outstanding, and its stock most recently closed at $79.93 per share.