WASHINGTON (Reuters) - The U.S. Senate passed a bill on Tuesday that would increase fees that companies planning the biggest mergers pay to government antitrust agencies and give those agencies bigger budgets.

The bill - co-sponsored by Democrat Amy Klobuchar, the top antitrust senator, and Chuck Grassley, the top Republican on the Senate Judiciary Committee - would lower the fee for smaller mergers under $161.5 million to $30,000 from $45,000. But for deals worth $5 billion or more, the fee would rise to $2.25 million from $280,000.