By Steve Keating

NEW YORK (Reuters) - Britain's Jamie Murray and Brazil's Bruno Soares swept the Spanish duo of Pablo Carreno Busta and Guillermo Garcia-Lopez 6-2 6-3 to win the U.S. Open doubles on Saturday for their second grand slam title of the year.

Murray and Soares had each lost in the Flushing Meadows final with a different partner -- Murray last year with Australian John Peers, and Soares in 2013 with Austrian Alexander Peya.

They made sure the trophy would not slip away a second time, adding the U.S. Open to the Australian Open title they won to start the year.

Fourth-seeded Murray and Soares become the first team to win multiple slam doubles titles in a season since American brothers Bob and Mike Bryan won three in 2013.

Murray, the brother of twice Wimbledon singles champion Andy Murray, became the first British man to claim the U.S. Open doubles crown since Roger Taylor in 1972, while Soares is the first Brazilian to land the title.

Andy Murray, the Olympic gold medalist in Rio this year, lost in the U.S. Open singles quarter-finals to Kei Nishikori of Japan.

By the measure of grand slam tournaments won this year, elder brother Jamie now has bragging rights, leading Andy 2-1.

He told reporters he is playing the best tennis of his career, and that his younger brother's success this year has helped with motivation.

"Just seeing him doing so well and wanting to have some of that success as well," Murray said of how his younger brother's recent string of big wins has made him work harder.

There is still a huge gap in career prize money between the brothers -- Andy has won nearly $50 million since turning pro in 2005, while doubles specialist Jamie has collected around $2.3 million since 2004.

The brothers have played together at times, but the elder Murray made clear that he considers the partnership with Soares a better fit.

"With Andy it's not so easy. Great players, they do what they're going to do," Murray said, adding that it was sometimes hard to proffer advice to his brother on court.

"With Bruno, we're on an even keel."

On Saturday, Murray and Soares prevailed over the Spanish duo by playing a more traditional quick-to-net doubles game that proved effective against their opponents' strong groundstrokes and tendency to hammer shots from the baseline.

Neither Murray nor Soares had won a men's grand slam doubles title before this year. Soares said the duo's goal is to become the world's top-ranked doubles team.

(Joshua Schneyer contributed reporting; Editing by Larry Fine and Andrew Both)