ZURICH, April 6 (Reuters) - Credit Suisse has substantially reduced the vast bulk of its exposure to Archegos, a source familiar with the matter said, adding some residual risk remained despite its positions having been substantially eliminated. Switzerland’s second-largest lender on Tuesday announced an estimated loss of 4.4 bln Swiss francs ($4.69 bln) from its relationship with Archegos Capital Management LP after offloading over $2 billion worth of stock to end exposure to the troubled investor. The scandal-hit bank now expects to post a loss for the first quarter of around 900 million Swiss francs. The Archegos fallout is the second major scandal for Credit Suisse in just over a month after the collapse of Greensill Capital, which led to the closure of its $10 billion supply chain funds which invested in bonds issued by Greensill. That matter had not resulted in a material loss for the bank in the first quarter, the source said, as the bank does not hold trading exposure to Greensill. (Reporting by Brenna Hughes Neghaiwi and Oliver Hirt Editing by Rachel Armstrong)