; and (3) increases in contributions or decreases in plan liabilities which are scheduled to take effect in future plan years may be taken into account in connection with a plan amendment if they have been agreed to in writing or otherwise formalized by the date the plan amendment is adopted. 805. Composite plan restrictions to preserve legacy plan funding (a) Treatment as a legacy plan (1) In general For purposes of this part and parts 2 and 3, a defined benefit plan shall be treated as a legacy plan with respect to the composite plan under which the employees who were eligible to accrue a benefit under the defined benefit plan become eligible to accrue a benefit under such composite plan. (2) Component plans In any case in which a defined benefit plan is amended to add a composite plan component pursuant to section 801(b), paragraph (1) shall be applied by substituting defined benefit component for defined benefit plan and composite plan component for composite plan . (3) Eligible to accrue a benefit For purposes of paragraph (1), an employee is considered eligible to accrue a benefit under a composite plan as of the first day in which the employee completes an hour of service under a collective bargaining agreement that provides for contributions to and accruals under the composite plan in lieu of accruals under the legacy plan. (4) Collective bargaining agreement As used in this part, the term collective bargaining agreement includes any agreement under which an employer has an obligation to contribute to a plan. (5) Other terms Any term used in this part which is not defined in this part and which is also used in section 305 shall have the same meaning provided such term in such section. (b) Restrictions on acceptance by composite plan of agreements and contributions (1) In general The plan sponsor of a composite plan shall not accept or recognize a collective bargaining agreement (or any modification to such agreement), and no contributions may be accepted and no benefits may be accrued or otherwise earned