20 C.F.R. § 702.281

(a) Every person claiming benefits under this Act (or the representative) must promptly notify the employer and the district director when:

(1) A claim is made that someone other than the employer or person or persons in its employ, is liable in damages to the claimant because of the injury or death and identify such party by name and address.

(2) Legal action is instituted by the claimant or the representative against some person or party other than the employer or a person or persons in his employ, on the ground that such other person is liable in damages to the claimant on account of the compensable injury and/or death; specify the amount of damages claimed and identify the person or party by name and address.

(3) Any settlement, compromise or any adjudication of such claim has been effected and report the terms, conditions and amounts of such resolution of claim.

(b) Where the claim or legal action instituted against a third party results in a settlement agreement which is for an amount less than the compensation to which a person would be entitled under this Act, the person (or the person's representative) must obtain the prior, written approval of the settlement from the employer and the employer's carrier before the settlement is executed. Failure to do so relieves the employer and/or carrier of liability for compensation described in section 33(f) of Act, 33 U.S.C. 933(f) and for medical benefits otherwise due under section 7 of the Act, 33 U.S.C. 907, regardless of whether the employer or carrier has made payments of acknowledged entitlement to benefits under the Act. The approval must be on a form provided by OWCP and must be filed, within thirty days after the settlement is entered into, with the district director who is administering the claim.