Kinder Morgan Inc. Executive Chairman Richard Kinder purchased about $9.3 million worth of the company's common stock, according to a May 30 SEC filing.

Kinder, a co-founder of the company, bought 500,000 shares at about $18.58, bringing the total amount of shares he owns to 234.7 million, according to the filing.

The transaction was filed the same day as the completion of Kinder Morgan Canada Ltd.'s C$1.75 billion initial public offering.

After falling 4.3% on May 30, Kinder Morgan Inc.'s shares rose 1.7%, to $18.74 on May 31.