Blackstone has completed its acquisition of the 753k SF office properties at 555 and 575 Market St from John Hancock Real Estate. The company plans a major upgrade of the facilities lead by Equity Office, Blackstone’s wholly owned real estate affiliate, and hopes to relocate its Northern California headquarters there. The selling price was not disclosed.

The two buildings are 93% leased and count Uber, TIBCO Software, PNC Bank and Bank of San Francisco as clients.

“Beyond the strength of the tenant base in Market Center, the project’s timeless architecture, excellent views, irreplaceable central location and close proximity to public transportation were all positive factors affecting the acquisition,” said Equity Office Western Region managing director Frank Campbell.

The new owner is planning to upgrade both buildings, placing an emphasis on improving common areas, adding more retail and fitness offerings, and sustainability. To attract companies looking for creative offices, Equity Office also plans to build new tenant suites.

CBRE will continue to lead leasing efforts for the building, lead by Bill Cumbelich, Tom Poggi and Alexis Walsh.

Eastdil Secured repped John Hancock, and Blackstone repped itself.