* Change eliminates extra day to schedule
* Tournament will be 15 days long in 2013-14
* Prize money to increase to $50 million by 2017 (Removes redundant word from 1st paragraph)
NEW YORK, March 20 (Reuters) - The U.S. Open will revert to a 14-day tournament from 2015 after United States Tennis Association (USTA) officials reached an agreement with players on restructuring the playing schedule and increasing prize money.
The USTA announced in December it was adding an extra day in 2013 and 2014 to the last grand slam of the year to give players a day off between the semi-finals and final, extending the tournament to 15 days with the men's final being played on a Monday.
But after discussions with players, the USTA announced on Wednesday that the finals would move back to their traditional time slots from 2015, with the men's championship on Sunday and the women's title match on Saturday.
"We've had conversations for the past several years with the players about the advisability of playing back-to-back on Saturday and Sundays for the semis and finals," U.S. Open tournament director David Brewer told a news conference.
"It's simply taken us some time to get to the point where structurally we could provide that promised day of rest, and the day of rest is now locked and loaded going forward."
The men's semi-finals, which have generally been held the day before the final as part of the U.S. Open's controversial "Super-Saturday", would be brought forward by a day to Friday to give the players a rest.
The men's first round, which had been spread over three days, will be held over two days, bringing the U.S. Open in line with the other grand slams.
The changes will not come into effect until 2015 because the initial changes had already been locked in as part of an agreement with the Association of Tennis Professionals (ATP) and Women's Tennis Association (WTA).
The five-year deal also included a hefty increase in prize money for the U.S. Open. Officials had already announced this year's event would increase by $4.1 million to $33.6 million, but said the total purse would be raised to $50 million by 2017.
"Over the last year, (we've) had some spirited discussions (with players) but nothing like a threat," USTA executive director Gordon Smith said.
"We knew that we would be going up on prize money, as our income increases and frankly as the needs of players have increased.
"We have to recognise that the players mean everything to the Open and they're incredibly valuable to the sport and valuable to the success of the Open, and we have to reward them accordingly."
The U.S. Open programme has been hotly debated by players for years after rain delays wreaked havoc on the event.
The tournament has spilled into a third week for each of the past five years because of weather delays, triggering complaints over why the showcase courts are not covered.
Wimbledon and the Australian Open both have retractable roofs over their centre courts and the French Open has announced plans to do the same at Roland Garros but the USTA says it is too expensive to do in New York.
The problem has been compounded by the congested schedule for the finals, which prompted the decision to make changes.
"These increases are the largest in the history of the sport, representing a significant step forward in truly recognizing the input the players have in the success of the U.S. Open," ATP president Brad Drewett said in a statement.
"We also welcome the decision from the USTA to adopt a schedule with the men's semi-finals completed by Friday and the final on Sunday, from 2015 onwards." (Editing by Gene Cherry)