Total compensation for U.S. workers -- the cost of fringe benefits and payroll taxes as well as wages and salaries -- rose 2.3 percent in the three months ended in September, the Labor Department reported yesterday.

The rise in wage and salary rates along was 2.2 percent in the quarter, compared with an increase of 2.1 percent in the same three months of 1979. For the year ended in September, wages and salaries went up by 9.4 percent.

The Labor Department has been collecting the figures for total compensations only since the beginning of the year, and they are not yet seasonally adjusted. The rises in the first two quarters of the year were 2.7 and 2.3 percent, respectively.

In a separate report, the department said that strikes last month were fewer and less costly in terms of working time lost than in September.The working time lost to strikes, at 1.3 days per thousands, was the lowest October level since 1972.

Lay-off rates in manufacturing declined slightly in October, the Labor Department said in a third report issued yesterday. After seasonal adjustment the lay-off rate decreased by 0.1 percent to 1.4 percent last month. It was 0.3 percent higher than a year earlier.

New hires also dropped off slightly last month, falling by 0.1 percent to a rate of 2 per hundred employes, a full 1 percent below the October 1979 level. The total accession rate -- which includces new hires, recalls and transfers from other offices or factories within the same company -- rose 0.1 percent to 3.9 percent in October.

Rehiring of laid-off workers clearly has been the main factor behind increasing employment. The recall rate for workers in manufacturing was up 0.4 percent last month from a year earlier. It seems that workers are still rather gloomy about job prospects as the seasonally adjusted quit rate, which partially reflects workers' assessment of other job opportunities, has not moved from a low 1.3 percent between July and October.

The wages and salaries figures released yesterday show that in the three months from June to September union workers' pay gains at 2.9 percent, were higher than those of nonunion labor, which average 1.8 percent. Workers in manufacturing had pay rises averaging 2 percent.

Those in durable goods industries averaged rises of 2.5 percent in the three months, compared with 1.2 percent for nondurable goods industries.

Blue-collar workers had higher wage and salary rises and bigger compensation increases than white-collar workers. Blue-collar workers had increases of 2.7 percent in compensation, while white-collar workers averged 2 percent and service workers 2.1 percent. Wage rises average 2.4 percent, 2.1 percent and 1.7 percent respectively for those groups.