The portfolio sale included full stakes in assets with vintages of 2013 and older and other partial stakes.
Pantheon Senior Debt Secondaries III has raised nearly $2.4bn after launching in October last year.
The sector's rapid growth has impacted pricing in the secondaries market and shifted some large buyers' behaviour.
The deal will allow GA to hold onto four assets, including website builder Squarespace.
Secondaries volumes in Q1-Q3 2024 match the full-year total for 2023, according to PJT's Q3 2024 Secondary Market Insight report.
TPG GP Solutions has been an active backer of GP-led continuation funds across North America and Europe following its launch in January 2022.
LP sales accounted for about $40bn, or 59% of activity in the first half, according to Jefferies’ half-year volume report.
The process involved moving a portfolio of buyout and growth stakes from North American and European managers into a new vehicle.
The firm has appointed 15 people this year alone, including to newly created finance director and head of tax roles.
The firm, founded by a former StepStone partner, focuses on GP-leds and direct secondaries.