Can an employer terminate a defined benefits pension plan when a surplus has been realized independently of the terms of the Plan?

As for the application of Saunders v. Vautier, Bastarache J. wrote, referring to a defined benefits pension plan, such as is in issue here, that: … The employer assumes the risk in such a plan; when interest rates and investment returns are high, a surplus will be realized, and when the economy changes, unfunded liabilities will often result. The goal is to require contributions by the employer that are sufficient to provide the defined benefits over long periods of time in spite of market fluctuations. To permit termination of the Plan when a surplus has been realized independently of the terms of the Plan is not consistent with its object or the applicable statutory regime. The contract clearly contemplated a continuing plan supported by a permanent Fund; segregation of the Fund by “closing” the Premier Plan was not possible. It is therefore an error to infer that the rule in Saunders v. Vautier can in effect create a manner of realizing on the actuarial surplus (the Fund) in violation of the terms of the Plan. In the case of this pension Plan, absolute entitlement to the surplus would only occur once the surplus becomes real, that is, once the Plan and Trust had been terminated. Rogers, supra, paragraph 90