CHICAGO -- Standard & Poor's Corp. on Friday assigned a negative rating outlook to the Chicago Board of Education while affirming the BBB rating on the board's $75 million of outstanding general obligation debt. A negative rating outlook also was assigned to two bond issues done on behalf of the board by the Public Building Commission of Chicago. That debt, $9.45 million of Series 75A bonds and $4 million of Series 76A bonds, also was confirmed at BBB. Debt service payments on the bonds are made by lease payments by the board to the building commission. The rating agency's action was taken "due to increasing pressure on the board's finances and operations," according to a news release put out by the rating agency. Todd Whitestone, a senior vice president at Standard & Poor's, said the rating agency was particularly concerned about the board's use of $78 million in not-yet-agreed-to wage and benefit concessions from school employee unions.