在国际贸易中，买卖双方经常需要通过书面形式进行沟通。当卖方希望对买方提出的报价进行修改时，通常会使用反还盘信函来表达自己的意见。下面是一封用英文撰写的反还盘信函示例：

**[公司名称]
[公司地址]
[邮政编码]
[日期]

[收件人名称]
[公司名称]
[公司地址]
[邮政编码]

Dear [收件人姓名],

Subject: Revision to Quotation

Thank you for your recent inquiry and for the opportunity to provide a quotation. We appreciate your interest in our products.

After reviewing your request, we would like to make some adjustments to our initial offer. The original quotation was based on specific terms and conditions which have now been reconsidered due to certain factors such as market fluctuations or changes in production costs.

The revised details are as follows:

  1. Price: The unit price has been updated to \([新价格] per [单位], down from the initially quoted \)[原价格].
  2. Quantity: We can now supply a minimum order quantity of [数量下限], compared to the previous requirement of [原数量下限].
  3. Delivery Terms: We propose changing the delivery terms to CIF (Cost, Insurance & Freight) instead of FOB (Free on Board).
  4. Payment Terms: Our preferred payment method will be a 30% deposit upon confirmation of order, with the remaining balance payable before shipment. Alternatively, open account arrangements can be discussed.
  5. Lead Time: The lead time for production and delivery will be extended by [天数] days to ensure quality control measures.
  6. Warranty: All products come with a standard warranty period of [保修期限], covering any defects in material or workmanship under normal use conditions.

We hope these modifications meet your expectations and allow us to proceed with this transaction smoothly. Please let us know if there are any aspects that require further negotiation or clarification. Your prompt response is appreciated so that we can confirm final details and move forward accordingly.

If you agree to these terms, please signify acceptance by returning a copy of this letter along with your purchase order number at your earliest convenience. If you have any questions or concerns, feel free to contact me directly via email or phone listed below.

Thank you again for considering our proposal, and we look forward to establishing a long-term business relationship with your esteemed company.

Best regards,

[Your Name]
[Your Position]
[Your Email Address]
[Your Phone Number]

以上内容仅供参考，实际写作时应根据具体情况调整相关信息和表述方式。此外，确保所有重要信息准确无误，并且符合双方之前协商一致的内容。