WASHINGTON, May 21 (Reuters) - The U.S. labor market will strengthen significantly next year, with monthly job growth expected to average 200,000, according to a new survey published on Monday.

The National Association for Business Economics forecast the unemployment rate at 7.5 percent by the end of 2013.

The survey of 54 economists painted a fairly upbeat picture of the labor market, which has slowed in recent months after job creation surged early in the year.

"Economists continue to see things pick up, even if it's just slightly from pretty low levels," said Shawn DuBravac, NABE outlook survey and chief economist at the Consumers Electronics Association.

The survey, conducted between April 19 and May 2, forecast nonfarm payroll increases averaging 188,000 per month this year and the unemployment rate at 8.0 percent by the fourth quarter.

Job growth averaged 254,000 per month between December and February, but cooled to an average of 134,500 in the past two months.

Most economists view the moderation as payback from an unusually warm winter that pulled forward hiring in the weather-sensitive sectors of the economy. The jobless rate has dropped by 1 percentage point to 8.1 percent since August.

Back in February, economists surveyed by the NABE had forecast employment gains averaging 170,000 per month this year and 183,000 in 2013.

The jobless rate had been seen at 8.1 percent by year end and 7.6 percent by the fourth quarter of 2013.

There was no change in growth forecasts, with gross domestic product averaging 2.3 percent this year and accelerating to 2.7 percent in 2013. However, house prices are expected to rise 0.5 percent by the end of this year. They were previously seen flat. (Reporting By Lucia Mutikani; Editing by Chizu Nomiyama)