STANADYNE <STNA.O> PURCHASES AMBAC STAKE Stanadyne Inc said it has acquired a substnatial majority of AMBAC S.p.A.'s outstanding stock from <AIL Corp>, the successor to United Technologies Corp's <UTX> Diesel Systems Division for undisclosed terms. In addition to purchase a majority of the Brescia, Italy, based company, Stanadyne said, it acquired a minority interest in AMBAC's U.S. operation headquartered in Columbia, S.C.