Shares of online music site

MP3.com

(MPPP)

skyrocketed Monday, the first day of trading since the company signed a licensing agreement with

Broadcast Music Inc.

, the organization that administers performance royalties for songwriters.

That deal, announced late Friday, gives MP3.com the right to make available the BMI repertoire of more than 4.5 million songs from within the MP3.com site.

MP3.com shares climbed 3 3/16, or 31%, to 13 9/16 in late trading Monday, reaching their highest price in three weeks. (MP3.com finished up 3 1/4, or 32%, at 13 5/8.)

San Diego-based MP3.com saw its shares get

pounded in late April after it lost a copyright infringement lawsuit filed by the five major record labels.

The suit involved MP3.com's creation of a database of more than 80,000 albums that allows users to effectively store music digitally and then access it via any computer connected to the Internet.