DDi Europe, a unit of DDi ( DDIC), agreed to acquire Thomas Walter, a British printed circuit board maker, for $30 million in cash. DDi, which makes components for electronics manufacturers, expects to close the deal early next month. The announcement came on the same day that Lehman Brothers downgraded DDi, which is based in Anaheim, Calif., to market perform from strong buy. In the Nasdaq regular session, DDi closed at $23.13, down 87 cents on the day. Though after-hours trading was slow, the stock lost 6 cents to $23.06 on Island.