After a research and development period marred by various legal, financial, and logistical headaches, Uber (UBER  ) is letting go of its autonomous vehicle division and turning over the remaining assets to the tech startup Aurora.

Uber Advance Technologies Group started its research in 2015 and released the first self-driving cars in a limited test in Pittsburgh in 2016. Testing took place first in San Francisco before relocating to Arizona after California revoked their registration. The program was marked by two major accidents, one including the death of a woman in Arizona.

However, after years of trials and tribulation, Uber seems to be done with its foray into autonomous vehicles. On Monday, the company announced that it would be turning over its autonomous vehicle efforts to Aurora, a tech startup specializing in AVs. As part of the deal, Uber will also invest $400 million in the firm, and CEO Dara Kosrowshahi will join Aurora's board of directors.

"With the addition of ATG, Aurora will have an incredibly strong team, and technology, a clear path to several markets, and the resources to deliver," co-founder and current CEO of Aurora Chris Urmson said. "Simply put, Aurora will be the company best positioned to deliver the self-driving products necessary to make transportation and logistics safer, more accessible, and less expensive."

Uber isn't the only firm with interests in Aurora, which has garnered backing from Hyundai (HYMTF  ) and Amazon (AMZN  ).

The reaction to Uber's news, if there was one, doesn't appear to have been positive. Uber shares slipped 1.4% on Monday, sliding from $54.59 to $53.80. Uber's shares have fluctuated heavily in the days since, going as low as $52.52 and as high as $55.91 through the first half of the week. At the time of writing, with an hour left until markets close on Wednesday, Uber stands at $53.91, 1.24% down from Monday's opening price.