Seagate Technology said it would buy rival computer disk-drive maker Maxtor for $1.9 billion in stock. Under terms of the deal, which is expected to be completed in the second half of 2006, Maxtor shareholders will receive 0.37 shares of Seagate common stock for each Maxtor share they own. Seagate shareholders will own about 84 percent and Maxtor shareholders will own about 16 percent of the new combined company.