Music rights investor Concord is preparing to increase its offer for Hipgnosis Songs Fund Ltd. to more than $1.5 billion as it seeks to beat rival suitor Blackstone (NYSE: BX), Bloomberg News reported.

The Nashville-based company, whose bid is backed by Apollo (NYSE: APO), could announce the revised proposal as soon as the coming days, according to Bloomberg. Hipgnosis — which owns song catalogs from Blondie, the Kaiser Chiefs and the Red Hot Chili Peppers — has been the subject of a bidding war in recent weeks.