Jacobs, son of Qualcomm co-founder Irwin Jacobs, had disclosed his plans to acquire the chipmaker to board members, sources told the newspaper.
He pitched his plan to several investors, including SoftBank, one source told the FT.
Qualcomm and Softbank declined to comment to the FT.
Jacobs resigned last week from his role as chairman, as the San Diego-based chipmaker resisted an aggressive takeover attempt from Singapore's Broadcom.
That bid was shut down by President Donald Trump earlier this week, amid national security concerns.
As of the Thursday close, Qualcomm had a market value of about $88.66 billion, according to FactSet.