Shares of Covad Communications Group Inc. jumped nearly 51 percent Wednesday after the high-speed Internet access company announced it resolved an antitrust lawsuit and other disputes with Verizon Communications Inc.

As part of the deal, Covad expanded its line-sharing agreement with Verizon, allowing it to offer its Digital Subscriber Line services over lines sold by Verizon voice resellers. It also announced a line-sharing agreement with MCI, which is being acquired by Verizon.