(Reuters) – Amazon.com Inc said on Tuesday it would raise its minimum wage to $15 per hour for U.S. employees from next month, seeking to head off criticism of working conditions at the world’s second most valuable company.

The online retailer said it would now lobby in Washington for an increase in the federal minimum wage and urged its competitors to follow its lead as the union-led “Fight for Fifteen” movement pushes for higher remuneration.

The new minimum wage will benefit more than 250,000 Amazon employees in the United States, as well as over 100,000 seasonal employees who will be hired at sites across the country this holiday, the company said.

“We listened to our critics, thought hard about what we wanted to do, and decided we want to lead,” founder and Chief Executive Jeff Bezos said in a statement.

“We’re excited about this change and encourage our competitors and other large employers to join us.”

Amazon, which became the second company after Apple to cross $1 trillion in market value last month, paid its U.S. employees on average $34,123 last year. Bezos is listed by Forbes as the world’s richest man with a net worth of nearly $150 billion.

Amazon’s current minimum hourly wage starts at around $11 and analysts said the raise would cost it $1 billion or less annually and be offset by a recent $20 increase in the cost of Prime memberships.