Multiple unions which represent about 110,000 University of California workers are seeking to force the University divest its holdings with private investment management company Blackstone Inc, including $4 billion dollars the University recently invested in Blackstone’s massive Real Estate Investment Trust (REIT).

In a letter date Friday, the unions complained that the University’s patronage of the private equity firm will worsen housing shortages, which presently affect both students and employees of the University.

Earlier this month the investment office of the University of California finalized a deal to invest $4 billion with the Blackstone Real Estate Income Trust. Blackstone’s REIT is the largest commercial real estate owner in the country.

In a letter to Jagdeep Bachher, the chief investment officer for the university system’s pension and endowment funds, union leaders wrote, “The University of California’s current housing investment strategy combined with the bolstering of Blackstone’s BREIT will only further deepen a hostile housing market for millions across California.”

Last month, thousands of graduate students at the university went on strike for a month over inadequate pay, which is exacerbated by the high cost of living in California, where housing is among the most expensive in the nation.

Blackstone has welcomed the University’s $4 billion cash injection into the firm’s REIT for wealthy individuals, after seeing the fund experience massive pressure due to increased withdrawal requests of late.

The REIT focuses its investments in sectors and markets where growth outpaces inflation, exploiting a fixed rate balance sheet which minimizes the risks of interest rate volatility. The REIT paid $12.8 billion for American Campus Communities, a student housing landlord last year.

The University confirmed it had taken possession of the letter, and it was being reviewed. The University also stressed a previous statement by chief investment officer Bachher, which notes the investment, “is an opportunity that comes only through strong, trusted partnership” and that the university’s investment in the REIT is an integral part of the university’s efforts to create a well-diversified real estate portfolio.