Warren Buffett’s Berkshire Hathaway Inc. may report that the value of its equity portfolio rose by $6.3 billion in the last three months of 2010 as holdings in Wells Fargo & Co. and Coca-Cola Co. rallied, Barclays PLC said.

The stock market rally may have helped boost Omaha, Nebraska-based Berkshire’s fourth-quarter unrealized net investment gains to $7.2 billion from $322 million in the year-earlier period, said Jay Gelb, a Barclays analyst, in a research report today. Unrealized gains, which reflect increases in the market prices of investments such a stocks and bonds, aren’t used to calculate net profits and losses.

Berkshire’s stock portfolio, which Buffett built in four decades as chief executive officer, benefited from advances in the top six holdings in the fourth quarter. Wells Fargo, the San Francisco-based bank that counts Berkshire as its biggest shareholder, posted a 23 percent gain, its largest in six quarters. Coca-Cola rose 12 percent. The portfolio was valued at about $57.6 billion as of Sept. 30, with more than a third of the assets in Atlanta-based Coca-Cola and Wells Fargo.

Berkshire’s book value, a measure of assets minus liabilities, “could rise about 6 percent, due to its significant exposure to equities,” Gelb said.

Fourth-quarter operating earnings may have risen 43 percent to $1,794 a share, Gelb said. Advances in the firm’s manufacturing, service and retail units and the addition of railroad Burlington Northern Santa Fe, which Buffett bought for $26.5 billion in February, may have helped results, Gelb said.

Buffett disclosed Berkshire’s U.S. stock holdings as of the end of the third quarter in a November regulatory filing. The fourth-quarter investments must be disclosed by mid-February.