PetSmart is being sold to a group of investors led by buyout firm BC Partners for $8.7 billion US.

The Phoenix-based pet store retailer says the investors have agreed to pay $83 per share in cash to the company. That's a 39 per cent increase from its closing price July 2 before the company announced it was looking to sell. The price is also a seven per cent increase from PetSmart's closing price Friday.

In addition to BC Partners, the buyers include StepStone and Canadian pension manager La Caisse.

"This transaction is a testament to the strength of the PetSmart brand and franchise and reflects the dedication and commitment of our 54,000 associates to serving our customers and delivering value for our company and our shareholders," said David K. Lenhardt, PetSmart's president and CEO. 

The sale requires approval from PetSmart shareholders.

LongView Asset Management says it will vote in favour of the deal. That fund owns 9 per cent of PetSmart and had been pressuring the company to sell since the summer.