Volkswagen AG and U.S. officials have reached a framework deal under which the automaker would offer to buy back almost 500,000 diesel cars that used sophisticated software to evade U.S. emission rules, two people briefed on the matter said on Wednesday. The german automaker has agreed to buy up to 500,000 disel vehicles. The shares of the company rose nearly 6 percent following the news.The proposal would apply only to the 2.0-liter diesel vehicles involved in the case — including certain Jetta, Golf, Beetle and Passat models — which make up the bulk of the rigged cars.