Google's U.S. lobbying bill more than tripled to $5 million during the first three months of the year amid increased government scrutiny of the Internet search leader's business and privacy practices.

The first-quarter expenses for political persuasion are by far the highest that Google Inc. has rung up for any three-month period since the company opened a lobbying office in Washington seven years ago.

At the same time last year, Google spent $1.48 million trying to make its points with U.S. lawmakers and regulators.

The total for the most recent quarter is more than the combined lobbying bills among four of Google's biggest rivals. Microsoft Corp., Apple Inc., Yahoo Inc. and Facebook Inc. spent a combined $3.6 million in the first quarter.