The music industry may be struggling to make money in the streaming age, but one part of the business has been growing consistently: payments to songwriters.

BMI, one of the two big agencies in the United States that handle the licensing when songs are played on the radio or streamed online, plans to announce on Thursday that it exceeded $1 billion in annual revenue for the first time, led by rapid growth in digital music.

BMI, whose full name is Broadcast Music Inc., collected $1.013 billion for the 12 months that ended in June, up almost 4 percent from the year before. That is slightly more than the $1.001 billion that its competitor Ascap took in last year.

In the number that will be scrutinized most closely by musicians — royalties — BMI paid slightly less than its rival. After deducting its operating expenses, BMI distributed $877 million to its thousands of members, including songwriters like Taylor Swift, Nile Rodgers and Adam Levine of Maroon 5. Last year, Ascap paid its members $883 million.