A source told Dow Jones Newswires that Ericsson is the front-runner in a process that is in its second round.
Other parties eying the business include Amdocs, according to the report.
Bloomberg reported last month that Nokia Siemens' BSS unit also has attracted interest from private equity firms. Sources told the same news agency that the business could yield as much as $377 million.
"As we announced in November, Nokia Siemens Networks believes that the future of our industry is in mobile broadband and we are intensifying our strategic focus on that area," a Nokia Siemens spokesman said in an emailed response to Bloomberg. "Business areas not consistent with the new strategy are planned to be divested or managed for value, and we have already announced the divestment of a number of these business."