Wilks Brothers LLC said April 12 it has acquired more shares of Trican Well Service Ltd., Canada’s largest pressure pumper.

Wilks Brothers, a private Cisco, Texas-based company, bought about 3.1 million additional common shares in Trican on the Toronto Stock Exchange.

So far this year, Wilks Brothers has acquired nearly 6 million shares of the Canadian company. The values of the transactions weren't disclosed.

With its most recent purchases, Wilks Brothers owns more than 23.8 million shares, or about 16%, of Trican.

Wilks Brothers was formed by Farris Wilks and his brother Dan Wilks in 2011. One of the brothers, Farris Wilks, is on Forbes' list of the world's billionaires.

According to Forbes, Farris and Dan Wilks also founded a fracking and oilfield services company named Frac Tech. The brothers sold their stakes in the fracking company in 2011 for $3.5 billion.

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