NEW YORK (TheStreet) -- Shares of TrueCar (TRUE - Get Report) were gaining 8.7% to $10.92 Friday following the announcement that the mobile car marketplace will end its relationship with car retailer AutoNation (AN) on July 31.

The end of the partnership comes after a four-month long contract dispute between the two companies, according to the Wall Street Journal.

TrueCar said it "formally demanded" that AutoNation abide by its "core principals" of providing vehicles at prices lower than MSRP with no negotiation, providing prompt and accurate inventory and sales data, and delivering "a transparent, professional, and hassle-free customer experience." AutoNation did not comply with the principals, according to the TrueCar.

"We have an unwavering and long-term focus on a transparent car-buying experience," TrueCar CEO and founder Scott Painter said in a statement. "We're grateful for the years of cooperation we've enjoyed with AutoNation, but could not make an exception for them."

AutoNation CEO Mike Jackson told the Wall Street Journal, "TrueCar generates about 3% of the 550,000 cars we sell annually, but they want all our customer information on every car we sell and we just can't agree to that. It is none of their business who our customers are."

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