Yahoo Inc. President Susan Decker purchased about $1.1 million of the Internet company's shares this week just after the stock hit a three-year low.

In a U.S. Securities and Exchange Commission filing this week, Decker revealed she had purchased about 47,000 shares of the company on August 7 and August 8.

The buy was Decker's first ever open-market stock purchase, according to filing tracker, and came one-day after the stock fell to $22.44 -- its lowest level since March 2004.

Decker's buy was just the fourth by any Yahoo insider in more than four years; and, the largest by any Yahoo insider in more than four years, InsiderScore analysts wrote in a research note on Friday. The buy also bucks a trend in the Technology sector, where insiders have been sitting out the recent buying binge.

Most of Decker's holdings in the company have been acquired through restricted stock awards.

She now holds about 424,700 shares of the company.

She was named president of the company two months ago, as part of a management shuffle, to oversee Yahoo's advertising and media business operations. Decker had previously been the company's chief financial officer.

Decker paid average prices ranging from $23.40 and $23.68 for her shares, according to the filing.

Since Decker's purchase Yahoo shares have climbed about 3.2 percent.

Yahoo shares were up 8 cents at $23.88 in morning trading on the Nasdaq on Friday.

(Reporting by Emily Chasan)