Potential bidders are considering offers of between $100 million and $120 million for the Baltic Exchange, the shipping-industry marketplace that is one of the world’s oldest exchanges, according to people familiar with the matter.

Interested parties include the Singapore Exchange, which disclosed it had made a nonbinding bid for the London-based exchange on February 26. Platts, a unit of McGraw Hill, and CME Group, could also make offers, but haven't made official bids, according to these people.