The publicly traded fund's gross revenue declined during the year ending in March based on one-time costs and a tough year-ago comparison.
CEO Golnar Khosrowshahi says Reservoir's strategy is "to become the largest holder of Arabic music copyrights."
The third-largest label marked the second straight quarter of lackluster results for its recorded music division, with revenue roughly flat over the year-ago period.
Slow quarter for new releases puts a drag on streaming revenue, but recent Ed Sheeran and Jack Harlow albums could boost WMG's second half.
The stock climbed 15% on Friday as the company beat consensus with over $3 billion in revenue and forecast a strong year ahead.
Overall, the tech giant beat analyst expectations for the quarter, delivering revenue of $94.8 billion.
Revenue for the concert promotion giant was up 73% over last year, generating $3.1 billion.
Releases by Tomorrow x Together and Seventeen helped offset a sharp drop in concert revenue for the K-pop giant.
Streaming revenue, given a boost from hits by Miley, SZA and others, boosted recorded music and publishing revenue in a record-setting year.
Growth in first quarter coming largely from investments and paid streaming overseas, especially in Asia Pacific and Latin America.
