37 C.F.R. § 1.565 : Patents, Trademarks, and Copyrights — UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE — GENERAL — RULES OF PRACTICE IN PATENT CASES — EX PARTE REEXAMINATION OF PATENTS —EX PARTE REEXAMINATION — Concurrent office proceedings which include an ex parte reexamination proceeding

(a) In an ex parte reexamination proceeding before the Office, the patent owner must inform the Office of any prior or concurrent proceedings in which the patent is or was involved such as interferences, reissues, ex parte reexaminations, inter partes reexaminations, or litigation and the results of such proceedings. See §1.985 for notification of prior or concurrent proceedings in an inter partes reexamination proceeding.
(b) If a patent in the process of ex parte reexamination is or becomes involved in litigation, the Director shall determine whether or not to suspend the reexamination. See §1.987 for inter partes reexamination proceedings.
(c) If ex parte reexamination is ordered while a prior ex parte reexamination proceeding is pending and prosecution in the prior ex parte reexamination proceeding has not been terminated, the ex parte reexamination proceedings will usually be merged and result in the issuance and publication of a single certificate under §1.570. For merger of inter partes reexamination proceedings, see §1.989(a). For merger of ex parte reexamination and inter partes reexamination proceedings, see §1.989(b).
(d) If a reissue application and an ex parte reexamination proceeding on which an order pursuant to §1.525 has been mailed are pending concurrently on a patent, a decision will usually be made to merge the two proceedings or to suspend one of the two proceedings. Where merger of a reissue application and an ex parte reexamination proceeding is ordered, the merged examination will be conducted in accordance with §§1.171 through 1.179, and the patent owner will be required to place and maintain the same claims in the reissue application and the ex parte reexamination proceeding during the pendency of the merged proceeding. The examiner's actions and responses by the patent owner in a merged proceeding will apply to both the reissue application and the ex parte reexamination proceeding and will be physically entered into both files. Any ex parte reexamination proceeding merged with a reissue application shall be concluded by the grant of the reissued patent. For merger of a reissue application and an inter partes reexamination, see §1.991.
(e) If a patent in the process of ex parte reexamination is or becomes involved in an interference, the Director may suspend the reexamination or the interference. The Director will not consider a request to suspend an interference unless a motion (§41.121(a)(3) of this title) to suspend the interference has been presented to, and denied by, an administrative patent judge, and the request is filed within ten (10) days of a decision by an administrative patent judge denying the motion for suspension or such other time as the administrative patent judge may set. For concurrent inter partes reexamination and interference of a patent, see §1.993.

37 C.F.R. §1.565

65 FR 76776, 12/7/2000, as amended at 69 FR 50001, 8/12/2004; 72 FR 18905, 4/16/2007