Shares of Tyco International ( TYC) were dropping in Instinet trading before the opening bell as news spread that the company spent about $8 billion during the past three years on about 700 acquisitions that weren't reported. News of the unannounced acquisition spree was reported Friday in Herb Greenberg's column on RealMoney.com and subsequently noted in Monday's editions of The Wall Street Journal. Separately, Tyco said it will repurchase all of the company's $4.5 billion of commercial paper at the scheduled maturities. To fund the purchases, Tyco will borrow from a bank credit line of $5.9 billion. The move will reduce earnings by up to 2 cents a share in fiscal 2002. Tyco's shares were dropping 10.5% to $33. The conglomerate has disclosed plans to split its operations, and Tyco's shares have dropped in recent weeks as investors worried about the company's complex accounting. Tyco is one of several companies that have been caught up in the bookkeeping worries that have occupied Wall Street since the collapse of energy trader Enron ( ENRNQ).