In New Jersey Automobile Full Insurance Underwriting Ass'n v. Liberty Mutual Insurance Co., 270 N.J. Super. 49, 53, 636 A.2d 550 (App. Div. 1994), the Court held that "a formal demand for arbitration must be filed within two years of the filing of the PIP claim in order to satisfy N.J.S.A. 39:6A-9.1." There is no question that Allstate did not formally make such a demand within the two-year period. However, the Court indicated that there are two methods reflected in N.J.S.A. 39:6A-9.1 to resolve reimbursement disputes between insurers: The statutory language in the second sentence of N.J.S.A. 39:6A-9.1 pertaining to insured tortfeasors: 'Shall be by agreement of the involved parties or, upon failing to agree, by arbitration,' is equally clear in showing the legislative intent that carriers seeking reimbursement from a tortfeasor's insurer should move for arbitration only upon failure to agree on entitlement and amount of payment. Thus, the Legislature contemplated two scenarios. The preferred one is agreement between the carriers. The alternative is binding arbitration. Underwriting, supra, 270 N.J. Super. at 53, 636 A.2d 550.