U.S. GDP is projected to grow at an annual rate of 2.2 percent this quarter, lower than a previous estimate, according to a survey by the Philadelphia Federal Reserve, released on Friday.

Respondents to the Survey of Professional Forecasters had previously expected a 2.4 percent in GDP growth this quarter, but revised their predictions downward. The rate of growth is forecast to increase in subsequent years, with 2.7 percent in 2013, three percent in 2014 and 3.1 percent in 2015

The forecasters are more optimistic about conditions in the labor market over the next four years than they were three months ago. Yet, their expectations for real GDP growth over the next two years are nearly unchanged, said Tom Stark, an assistant director of the Philadelphia Fed, in a statement.

The jobless rate is forecast to fall to 8.1 percent by the fourth quarter of 2012, and is projected to decrease further to 7.9 percent in 2013, 7.4 percent in 2014 and 6.7 percent in 2015.

Non-farm payroll employment is projected to grow by 160,100 per month in the first quarter and 141,900 jobs in the next quarter. The annual average for monthly gains is projected to be 144,100 in 2012 and 162,900 in 2013.

Inflation is forecast to average two percent. Forecasters also said that the chance of negative growth this quarter was less likely at 9.5 percent, down from a previous forecast of 16.6 percent.

The quarterly survey covers 45 professionals from various industries.