London Stock Exchange (LDNXF) said it would buy two fixed income trading and benchmarking assets from Citigroup (C - Get Report) , barely two months after a tie-up with Germany's Deutsche Boerse (DBOEY)  fell apart.

The U.K. stock exchange operator will buy The Yield Book and Citi Fixed Income Indices from the U.S. bank for $685 million, funded by cash on hand and bank debt. The Yield Book is a fixed income analytics platform, covering mortgage, government, corporate and derivative securities. Citi Fixed Income Indices, owner of the World Government Bond Index, compiles benchmarks and provides other associated data to clients across the globe.

Both assets will be folded into LSE's FTSE Russell Information Services division, which was picked up during the June 2014 acquisition of Russell Investments, and are expected to boost earnings from the first year onward.

This article was written by a staff member of TheStreet.