Unemployment in the metropolitan Washington area continued a recent decline last month, falling to 5 per cent of the total work force compared with 5.2 per cent the previous month and a national average of 7.8 per cent.

The D.C. Department of Manpower, which compiles jobs data for all area governments, also reported over the weekend that umemployment in the District of Columbia decreased to 6.9 per cent in December from 7.1 per cent in November and 8.4 per cent one year earlier, with all figures adjusted to reflect normal seasonal variations in work patterns.

Total area employment, not counting military personnel, was 1,386,700 last month, up 3,600 from November and up 24,100 from the end of 1975. The number of people out of work was 66,900 in December compared with 72,300 in November and 80,600 a year ago.

In the District, total employment was 322,100 last month, a gain of 5,600 over the previous 12 months. The number of people jobless fell to 22,000 from 23,800 in November and 26,500 a year earlier.

All sectors of the local economy reported higher employment during 1976 with the exception of state and local government, which declined to 165,700 from 166,500. In major components of the area labor market, federal government employment rose to 352,500 from 349,100; service industries, to 313,700 from 307,200; finance, insurance and real estate, to 79,700 from 77,600; retail and wholesale trade, to 273,000 from 264,000; transportation, communications and utilities, to 64,100 from 30,000; construction, to 71,600 form 69,300; and manufacturing, to 47,700 from 44,400.

In the District alone, city government payrolls declined to 44,500 from 47,000 but all other sectors showed more jobs.