Here, it is undisputed that the Agency provided the Union with two unsolicited written allegations of non-negotiability. See Response, Attach. 1 at 2-3; SOP, Attach. 1 at 2-4. As was its right, the Union chose not to file a negotiability petition from those unsolicited allegations. See 5 C.F.R. § 2424.11(c); AFGE, Local 3369,49 FLRA at 795. Consequently, its failure to do so did not bar the petition that was timely filed following receipt of a subsequent written allegation of nonnegotiability (that the Agency provided in connection with a settlement agreement to resolve an unfair labor practice (ULP) charge concerning the Agency’s alleged failure to bargain over this matter). See SOP, Attach. 10 at 1. Accordingly, we find that the Union’s petition is timely. Cf. AFGE, Local 3369, 49 FLRA at 795 (union ignored agency’s unsolicited allegation of non-negotiability, and requested written allegation from which it timely filed its petition).