A chunk of LyondellBasell (NYSE:LYB) 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 (NYSE: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.