Ram Ozeri reports to the news site The Marker that "The candidates for Comverse billing units acquisition are Amdocs and Oracle" (here, Hebrew). Both did not comment.
The publicly traded company (Comverse Technology Inc - NASDAQ:CMVT, market cap of $1.35B) has also holdings in other companies, mainly in Verint (NASDAQ:VRNT, market cap of $1.02B). Its "Comverse Segment" (see H1 2011 financial results below) includes several product lines, major ones being billing, Value-added Services and mobile internet products (PCRF/PCEF - here, here).
From the above and other reports it is not clear if the holding company is selling the whole segment or just its billing unit.
Recently, both Amdocs and Oracle have invested in Policy Management (PCRF) products - Amdocs acquired Bridgewater Systems (integration to be announced today - here) and Oracle launched its own product (here and here). Of course, the PCRF market is much smaller than billing.