Intercontinental Exchange, the parent company of the New York Stock Exchange, is in final negotiations to buy the Chicago Stock Exchange, Bloomberg reports. Terms of the deal were not disclosed.

News of Intercontinental Exchange's interest in the 136-year-old Chicago Stock Exchange broke last week, with sources close to the negotiations valuing a deal between $50M and $100M. It is the latest chapter in a two-year saga over the Chicago Stock Exchange. Chinese developer Chongqing Casin Enterprise Group announced a deal to buy the exchange in February 2016. Casin founder and Chairman Shenju Lu said his firm wanted to buy the exchange in order to open a pipeline for U.S. investors to buy into Chinese financial markets. A group of 46 congressmen called for an investigation into the deal, and raised questions as to Casin's motives and ties to the Chinese government. The deal fell apart last year.

Trade volume at the Chicago Stock Exchange accounts for only 0.5% of the $21 trillion U.S. equity marketplace, but the NYSE does acquire a license in another market without having to undergo a lengthy approval process by the Securities and Exchange Commission. NYSE, Nasdaq and CBOE Global Markets have spent the past few years acquiring licenses in other markets, partially because it gives each exchange votes in smaller markets on issues like infrastructure improvements.

Analysts also believe the NYSE can use the Chicago Stock Exchange as a testing ground to introduce cryptocurrency to the stock market. NYSE acquired Coinbase, one of the largest cruptocurrency exchanges, in 2015.