28 CFR §2.31

1. (a)Where a detainer is lodged against a prisoner, the Commission may grant parole if the prisoner in other respects meets the criteria set forth in § 2.18. The presence of a detainer is not in itself a valid reason for the denial of parole.
2. (b)The Commission will cooperate in working out arrangements for concurrent supervision with other jurisdictions where it is feasible and where release on parole appears to be justified.