A gauge of online demand for labor in the United States rose in April for a third straight month and posted its largest year-on-year percentage gain since July 2007, a private research group said on Thursday.

Monster Worldwide Inc, an online careers and recruiting firm, said its employment index rose to 133 points in April from 125 in March and is 10.8 percent above the 120 level a year ago.

The index peaked at 189 in May 2007 and April's reading is the highest since the 143 hit in November 2008. This month's yearly percentage gain is the highest since the 10.9 percent gain posted July 2007.

The monthly rise in April jobs demand was due in part to growth in job offerings from mining and energy-related companies, Monster said.

The positive momentum in the index is consistent with other economic indicators suggesting that we may be in the early stages of an economic recovery, said Jesse Harriott, chief knowledge officer at Monster.

The data adds to signs of a rebound in the labor market, as reports showed on Wednesday a growing trend of job demand from private companies, while plans for layoffs fell to their lowest level in four years.

From a forward-looking perspective we would hope this could be a solid indicator... that we would also see (growth) in the future months with the payroll numbers, said Jeff Quinn, senior director of research at Monster.

The U.S. government's closely watched non-farm payrolls report is scheduled for Friday. A Reuters poll shows economists expect to see 200,000 non-farm jobs were created in April.

The Monster index registered increases in 17 of 20 industries and 21 of 23 occupations monitored last month.

Online job demand was higher in all nine U.S. census regions, with the Mid Atlantic and New England areas registering the largest increases.

The report also comes ahead of the U.S. Labor Department's release of weekly initial claims for unemployment benefits, due later on Thursday and expected at 440,000 according to a Reuters poll.

The Monster Employment index is a monthly analysis based on a selection of corporate career sites and job boards. The margin of error is approximately plus or minus 1 percent.

(Reporting by Rodrigo Campos, Editing by Chizu Nomiyama)