Logitech ( LOGIY) said Wednesday it has agreed to buy Labtec ( LABT), a Vancouver, Wash., provider of computing, communications and entertainment accessories. Logitech, a maker of computer interface devices, offered to purchase all of Labtec's shares outstanding for $18 each. The company will pay $11 in cash and $7 in stock. The deal is valued at $125 million. Logitech expects to complete an exchange offer for Labtec's shares during late March or April. Shares of Logitech closed down 69 cents, or 2.2%, to $31 in the Nasdaq regular session.