Volvo Car Corp. and ride-hailing giant Uber Technologies Inc. have signed a 300 million agreement to co-develop autonomous sport-utility vehicles that will either be used as self-driving taxis or sold to consumers. The two companies will announce the joint project Thursday, saying the Swedish auto maker will conduct much of the initial engineering on a platform for an XC90 SUV that is capable of piloting itself. At some point, Uber will take that technology and use it as the foundation to develop its own self-driving vehicle technology. Volvo will do the same. Under the agreement, Uber will buy XC90 SUVs manufactured by Volvo.