The fund closed with total commitments of €17.1 ($17.6) billion.
The three new hires previously worked at SVB Capital.
The team joins with five existing investment funds and $500 million in capital commitments.
Kelly Cavagnaro joins from Columbia Threadneedle Investments.
The new hire spent the past 16 years at Vanguard Group, where he most recently served as senior director of consultant relations.
The firm has lifted five new employees from Aviva Investors.
Northwestern Mutual will acquire a minority equity interest in Sixth Street.
Dana Emery will relinquish her chair and ceo titles at the end of this year after more than 40 years with the firm.
The oversubscribed fund brings the firm’s total capital under management to approximately $1 billion.
The strategic, minority investment was made through Blackstone’s GP stakes business.