BPEA - which Sweden-based private equity fund EQT agreed to buy earlier this year in a deal worth 6.8 billion euros ($7.5 billion) - is working on a merger that could value the two portfolio companies at between $7 billion and $8 billion, the report added.
BPEA has notified Tricor and Vistra's creditors about the merger plan, the report said, citing people familiar with the matter.
The Hong Kong-based private equity firm acquired Tricor from buyout group Permira in November last year in a deal valuing the business expansion specialist at $2.76 billion including debt.
Baring Private Equity did not immediately respond to Reuters' request for comment.
(Reporting by Jaiveer Singh Shekhawat in Bengaluru; Editing by David Holmes)