Billionaire activist investor Carl Icahn’s investment firm cannot stop Southwest Gas Holdings Inc.’s board from potentially selling $1 billion worth of shares at a discounted price to fund an acquisition, a Delaware state judge ruled on Dec. 21.

Chancellor Kathaleen McCormick of the Delaware Chancery Court denied during a phone hearing Icahn Partners LP’s request to block a considered sale. She said the challenged deal had not happened yet and it was hard to imagine the harm a hypothetical transaction might cause.

Representatives for Icahn Enterprises and Southwest Gas did not immediately respond to requests for comment on the decision.

Icahn’s investment firm had sought to block gas distribution company Southwest Gas’ roughly $1.98 billion acquisition of Dominion Energy Questar Pipeline LLC, which was announced in October.

Icahn’s firm owns a roughly 4.8% stake in the company, much of which has been acquired since July, court documents show.

The Questar deal was announced shortly after Icahn penned a letter urging the board to focus on improving its share price instead of pursuing the deal.

Icahn’s investment firm later sued the Southwest Gas directors in November and accused the board of planning to sell the company’s shares at a discounted price to fund the Questar deal, according to the complaint.

Icahn Partners also alleged that the board was using the transaction to thwart the investor’s proxy campaign to replace the company’s 10 directors.

The investor said that the board members could sell the shares to an entity that would likely support their reelection.