Amazon reached an agreement with most of its workers in Spain on Monday, avoiding the full impact of a planned one-hour strike per shift on one of the busiest online shopping days of the year, according to local union group CCOO and the company.

Around 20,000 warehouse and delivery workers at Amazon's Spanish unit had been urged to walk out to demand better pay and working conditions on the so-called Cyber Monday discount day, when retailers aim to boost Christmas gift buying.

Only 5,000 Amazon delivery workers will continue with the protest, stopping work for the last hour of their shifts, after they considered the company's proposal for better pay conditions was not enough, said Douglas Harper, the leader of CCOO, the largest union at the U.S. retailer in Spain.

"The vast majority of our teams will continue to work as normal and there will be no impact on our operations for our customers," the company said in an emailed statement. "We are proud of the wages, benefits and safer working conditions that will be provided to our employees in Spain," Amazon added.

CCOO said it would continue negotiations with the company to improve pay and conditions at the local unit.

Amazon logistics workers on both sides of the Atlantic have complained about working conditions, with groups of workers and activists across Europe protesting against the U.S. e-commerce giant as recently as Friday.

On Black Friday, the day after the U.S. Thanksgiving holiday when many retailers slash prices to boost sales, groups in Britain, Germany, France and Italy tried to disrupt the company's operations.

Amazon had said deliveries of Black Friday orders would be reliable and timely. (Reporting by Corina Pons Editing by Mark Potter)