Telefonica de Espana SA says that it wants out of its 20% investment in the AT&T Microelectronica SA joint venture that gave AT&T Co the European semiconductor manufacturing base it wanted, and has offered to sell the holding to AT&T, which holds the remaining shares in the large-scale joint venture. Telefonica sees the sale of the holding as a means of raising some of the cash it will need to pay for the 20% of AT&T Network Systems it wants. The stake in the Spanish chip shop has been valued at about $34m. Telefonica’s Amper SA telecommunications equipment affiliate already holds 49% in the AT&T Network Systems Espana SA business, and Telefonica would also like to sell that holding to buy 20% of the entire European AT&T Network Systems. AT&T wants to limit Telefonica to only 15% and not 20% of AT&T Networks, and values 15% at $102.5m.