(Reuters) -Dominion Energy Inc abandoned the sale of a natural gas pipeline to unit of Warren Buffett’s Berkshire Hathaway Inc because of uncertainty over whether antitrust regulators would approve it, the companies said on Monday. Berkshire Hathaway Energy had planned to acquire Dominion’s Questar Pipelines for $1.3 billion in cash and the assumption of $430 million of debt, as part of a larger purchase of Dominion’s natural gas transmission and storage business. The Berkshire unit has said it bought the remaining assets, including more than 5,500 miles (8,850 km) of gas transmission pipelines and 775 billion cubic feet of gas storage, in November for $2.5 billion in cash after adjustments plus $5.6 billion of assumed debt. Monday’s announcement has no impact on that purchase, which represented about 80% of the original transaction value, including the assumed debt, the companies said. Dominion, based in Richmond, Virginia, plans to borrow money to repay the $1.3 billion to Berkshire, and repay the loan by year end after selling Questar to another buyer. It said the announcement would not affect its financial outlook. The transaction had been one of Berkshire’s largest in recent years. Undoing the Questar purchase will boost the Omaha, Nebraska-based conglomerate’s cash stake, which ended March at $145.4 billion. Buffett has struggled to deploy Berkshire’s cash as high valuations and the growth of special purpose acquisition companies make buying whole companies appear expensive. Berkshire has repurchased tens of billions of dollars of stock since late 2019. The conglomerate owns dozens of businesses such as the BNSF railroad and Geico car insurer, and stocks including Apple Inc and Bank of America Corp. Reporting by Arunima Kumar in Bengaluru and Jonathan Stempel in New York; Editing by Maju Samuel and Marguerita Choy Our Standards: The Thomson Reuters Trust Principles.