Bill Ackman and his beleaguered Pershing Square Capital Management will sell the remaining 6.6% stake it owns in railroad company Canadian Pacific Railway  (CP - Get Report) . The sale, announced late Wednesday, is the fund's latest move to unload shares in the wake of losses stemming from its investment in embattled Valeant Pharmaceuticals International (VRX) .

Pershing Square and CP issued separate statements Wednesday addressing the sale. Pershing reported that it had launched a public offering for the remaining 9.8 million CP shares held by the fund. The activist in April reported that it had cut its stake in CP to 6.6% from 9.1%. Pershing Square said in its release that it intends to use the proceeds of the sale to fund one or more new investments. 

"Canadian Pacific has completed an incredible transformation since our initial investment in 2011," Ackman said. "Hunter Harrison and Keith Creel have restored to greatness one of North America's top railroads and have set the company on the path to continued success."

The liquidation suggests that Ackman, who sits on the board of Canadian Pacific, is no longer going to agitate behind the scenes to push CP into making another major unsolicited bid after the railroad canceled hostile efforts in April to acquire Norfolk Southern (NSC - Get Report) . Ackman had been a major advocate for consolidation in the railroad space, arguing last year that Norfolk was "an ideal activist situation." In 2012, he engineered a board takeover at CP, in a major victory that pushed out the railroad company's CEO, Fred Green.

Pershing had acquired an original 12% CP stake in 2011, at prices ranging from $46.41 a share to $63.52 a share. On Friday, shares were down 2% in after-hours trading, valued at $144 a share.

The share sale likely has to do, partly, with efforts to try to balance Pershing Square's portfolio, which is struggling with its significant investment in Valeant. The drug company's stock price dropped by more than 50% on one day last year and trades at roughly $22.36 a share -- down from its high of about $262 a share in August 2015.

The stock price drop helped drive Pershing Square, once the darling of the activist investor community, to an abysmal -20.5% return net of fees for 2015.