Complex sentence: UNEP FI works closely with nearly 200 financial institutions who are Signatories to the UNEP FI Statements, and a range of partner organisations to develop and promote linkages between sustainability and financial performance.
Split into simpler sentences: UNEP FI works with a large number of financial institutes, around 200, who are Signatories to the UNEP FI Statements. They also work with a range of other partner organizations in order to produce and promote linkages between sustainability and financial performance.