 GLENDALE, Calif.--BUSINESS WIRE--PS Business Parks, Inc. NYSE:PSB today announced that its operating partnership, PS Business Parks, L.P., entered into a Fourth Amended and Restated Credit Agreement the Credit Agreement. The amendment and restatement, among other things, increases the aggregate principal amount of the unsecured revolving credit facility Credit Facility from 250 million to 400 million, and extends the maturity date to August 24, 2025, with two six-month extension o 