Opinion PER CURIAM.
Onсe again the Court must review a reverse-Freedom of Information Act (“FOIA”) case and focus on the sufficiency of an agency’s decision to release confidential commercial information over timely objection. The District Court granted summary judgment sustaining a decision of the General Services Administration (“GSA”) to release to competitors of AT & T Information Systems (“AT & T-IS”) under FOIA six documents containing confidential pricing information which AT & T-IS submitted to GSA as part of its response to a bid solicitation. Because the District Court departed from the administrative record by relying on post-hoc rationalizations for GSA’s action submitted by affidavit, we reverse with direction to remand the record to GSA so that it may сomply with the Administrative Procedure Act.
In 1983 GSA commenced a nationwide one-billion dollar program to modernize its telecommunications system by awarding regional contracts through competitive bidding. On March 1, 1985, AT & T-IS was selected as the successful bidder for the *1235 New England region, in the first procurement initiated under this plan. The procurement included station equipment, switches, and a switch management center, as well as various services, plus installation and maintenance. Electronic switches using computer software regulating the flow of telephone messages and computer data among some 29 locations in the region were involved. Each bidder was required to develop its own switching configuration. The number and size of the switches selected by a bidder to create an adequate, balanced system was doubly crucial because this in turn had a direct bеaring on the ultimate bid price.
Three days after the bid award to AT & T-IS, GTE Communications Systems (“GTE”), a competitor of AT & T-IS also involved in the New England procurement, filed under FOIA asking for AT & T-IS’s еntire proposal. On March 6, 1985, a GSA official notified AT & T-IS of GTE’s filing, stating:
I hereby request your comments on the releasability of your proposal, including the pricing section. What areas, if any, should be withheld? If you feel that any areas should not be released to GTE, explain why the releasе of such information would cause substantial competitive harm to your firm.
Joint Appendix (“J.A.”) at 139. Addressing FOIA exemption 4, 5 U.S.C. § 552(b)(4) (1982), 1 AT & T-IS presented in responsе a specific, detailed claim stating why its switching configuration and discount pricing strategy for components underpinning the final publicly disclosed bid price should be withheld as “commercial or financial” information within the meaning of the exemption. It emphasized the prosрect of further similar competitive bidding for other GSA regions and the harm to its position in the bidding that release of the detailed price data would cause.
AT & T-IS’s submission was examined. Its objection to releasing the identity of the systems’ configuration was accepted, but a decision was made within GSA to release to FOIA requesters AT & T-IS unit pricing of the equipment in each system covered by the proposal along with the price per system.
On April 9, 1985, GSA advised GTE it was releasing everything requested except for certain withheld materials, not here relevant. Thе letter did not withhold price data and contained no explanation or reason for releasing the price data contаined in the proposal file. At the same time, GSA sent a copy of the GTE letter to AT & T-IS with a cover letter in which the only substantive paragraph read as follows:
This is to advise you that we will release a complete copy of your proposal except thоse portions identified in the enclosed response to the requestor. In reaching our decision to release this information, we have carefully considered the comments in your letters. Your proposal, less the excepted items will be released to the requestor 5 working days from your receipt of this letter.
J.A. at 145.
AT & T-IS filed suit and moved for summary judgment. No basis for GSA’s determination appeared in the stipulatеd administrative record filed with the Court. GSA opposed the motion with a counter-motion for summary judgment, which it supplemented with a declaration by Harry H. Fuchigami of its Office of Information Resources Procurement, explaining why AT & T-IS’s request for withholding of price data had been rejected. The District Court, relying on the Fuchigami declaration, granted GSA’s motion.
See AT & T-IS v. GSA,
*1236
Chrysler Corp. v. Brown,
This rule applies to informal agency proceedings like those involved in this case,
see Doraiswamy v. Secretary of Labor,
GSA urges considerаtion of the Fuchigami declaration was proper under a limited exception allowing agencies to supplement the administrаtive record to provide “such additional explanations of the reasons for the agency decision as may prove necessary.”
Pitts, supra,
In view of the inadequacy оf the record, we must reverse with direction to remand to GSA for development of its reasons for deciding not to withhold. In so doing we exprеss no view on the merits of the dispute. We desire only to emphasize the clear necessity that reverse-FOIA cases must proceed with scrupulous regard for the separate roles of the agency involved and that of the reviewing courts.
Reversed and remanded.
Notes
. (b) This section does not apply to matters that are—
(4) trade secrets and cоmmercial or financial information obtained from a person and privileged or confidential;
. GSA argues that AT & T-IS is barred from challenging the District Court’s reliance on the Fuchigami declaration by its failure to object below. But AT & T-IS did expressly oppose the post-hoc character of the declaration, see J.A. at 3, 210 n. 16, 211 n. 17, 240; and the District Court rejected the argument, see 627 F.Supp. at *1236 1400-01. The issue is therefore properly presented for review.
