Berkshire Hathaway 's first-quarter profit more than doubled as the value of its investments grew and most of its businesses improved. The conglomerate that Warren Buffett built released its earnings report Saturday as thousands of shareholders streamed into an arena in Omaha , Nebraska, for the annual meeting. Berkshire said it earned $10.1 billion, or $7,027 per Class A share. That's up significantly from last year's $4.6 billion, or $3,200 per A share. This year's meeting is the first one that Buffett won't lead from the stage after Greg Abel was promoted to CEO in January. Attendance at the meeting is expected to be down somewhat this year. The paper value of Berkshire’s investments always has a major impact on its bottom line even though it hasn’t sold most of its stocks, but it did record a $5.8 billion gain on the stocks it did sell during the quarter. The value of the portfolio did slip to just over $288 billion.…