3Com Corp. said it is revising previously reported financial results because of a Securities and Exchange Commission review of its filings after its acquisition of U.S. Robotics Corp. 3Com Chief Financial Officer Chris Paisley said in a statement that the company will also be revising its first- and second-quarter filings for fiscal 1998 as soon as possible. The Santa Clara-based networking company will reduce the restructuring charge for U.S. Robotics recorded in the first quarter to $270 million from $426 million. The company is revising its 1997 earnings figures to reflect the adjusted charges and recombined results for the two companies. Earnings for the fiscal year were lowered to $500.5 million, or $1.41 a diluted share, from $597.6 million, or $1.69. 3Com stock fell $2.38 to close at $35.31 in Nasdaq trading during a broad technology sell-off.