The change "reflects the benefits we gain from Berkshire Hathaway's ownership, particularly our ability to reinvest in our businesses and take a long-term view of our customers' needs," Greg Abel, the unit's chief executive, said in a statement on Wednesday.

MidAmerican's new name also reflects a recent trend in which the company Buffett took over in 1965, when it was a failing textile maker, sees its name planted on an array of units.

Berkshire ranks fourth in Fortune magazine's list of the world's most admired companies.

"MidAmerican doesn't mean much to anybody. Berkshire does," said Andy Kilpatrick, who last week released a revised version of his book, "Of Permanent Value: The Story of Warren Buffett." "Having a recognized brand name could be a door opener for bringing in business."

In October 2012, a real estate brokerage owned by MidAmerican created the Berkshire Hathaway HomeServices brand, putting the Berkshire name on "For Sale" signs around the country.

Eight months later, the parent launched a new commercial property casualty insurance unit called Berkshire Hathaway Specialty Insurance. Berkshire's array of more than 70 newspapers, mostly acquired recently and including its hometown Omaha World-Herald, falls under its BH Media Group Inc. umbrella.

Berkshire still has many recognizable brands among the more than 80 businesses it owns, including Benjamin Moore paint, Dairy Queen ice cream, Fruit of the Loom underwear and Geico auto insurance.

In 2013, MidAmerican posted a $1.64 billion profit on revenue of $12.74 billion, and Berkshire's 89.8 percent stake contributed nearly 8 percent of the parent's overall profit. Berkshire had taken an initial 76 percent stake in 2000.

Berkshire Hathaway Energy is based in Des Moines, Iowa, has about $70 billion of assets and serves 8.4 million customers.

Its subsidiaries, including Oregon-based PacifiCorp and the Nevada-based NV Energy utility, for which MidAmerican paid $5.6 billion last year, will keep their names and continue to be run locally.

Berkshire will hold its annual shareholder meeting on Saturday in Omaha.