WASHINGTON — As Congress crafts legislation to impose new oversight on complex instruments blamed for hastening the financial crisis, a major sticking point has emerged over companies that use the derivatives to hedge risk.

Some lawmakers want to exempt so-called "end users" of derivatives from new capital and other requirements in the overhaul legislation. A potent coalition of about 170 companies that use derivatives — including Boeing Co., Caterpillar Inc., Ford Motor Co., General Electric Co. and Shell Oil Co. — has been lobbying Congress to say that regulation of derivatives without exceptions could severely increase costs for corporate America.