Apollo Global Management (APO.N) is nearing a buyout of PetSmart Inc (PETM.O) for about $8 billion in what would be the largest leveraged deal for a U.S. company this year, Bloomberg reported on Saturday, citing unnamed sources.

"New York-based Apollo is in late-stage talks to buy PetSmart for about $8 billion following an auction process that has been under way for weeks, said one of the people, who asked not to be identified because the talks are confidential," Bloomberg said.

It said the pet-supplies retailer has a market value of $7.72 billion. A private-equity deal with Apollo would top Blackstone Group LP's (BX.N) $5.4 billion purchase of industrial-products maker Gates Global LLC in July, Bloomberg said.