在合同有效期内，双方是否可以重新再谈价？

题目：在合同有效期内，双方是否可以重新再谈价

作者： 黄云峰诉讼律师         翻译： Benjamin Shi

魁北克省最近的一项法院判决涉及的问题是，当一方有意从市场变化中获得意外利润时，缔约方是否有义务重新谈判合同价格。

在这种情况下，魁北克水电公司签订了一份65年的合同，以固定价格购买发电厂产生的电力。在合同期限内，电力市场价格上涨。魁北克水电公司从低买高卖中获利丰厚。该发电厂声称魁北克水电公司有义务以公平或诚意重新协商合同价格以反映市场变化。

加拿大最高法院驳回了这一建议，并认为由于合同属于交易性质（而非关系性质），因此各方必须坚持讨价还价。虽然这个案件是根据魁北克省的民法典决定的，但它提醒人们，在合同有效期内，当其经济利益可能受到不可预测的市场波动影响时，必须谨慎签署合同。

英语原文：

A recent Quebec court decision dealt with the issue of whether contracting parties have a duty to renegotiate contract price when a party is positioned to reap unanticipated profits from changes in the market.  

In that case, Hydro Quebec entered into a 65-year contract to purchase electricity generated by a power plant at a fixed price.  During the term of the contract, the market rate for the electricity increased.  Hydro Quebec profited substantially from buying low and selling high.  The power plant alleged that Hydro Quebec owed a duty in equity or good faith to renegotiate the contract price to reflect the market change.  

The Supreme Court of Canada rejected that suggestion, and held that because the contract was of a transactional (instead of relational) nature, the parties must be held to their bargain.  While this case was decided under Quebec’s civil code, it serves as a reminder that one must be careful in signing a contract when its financial benefit may be affected by unpredictable market fluctuation during the term of the contract.