Maryland, Virginia and District residents would be able to compete for 50,000 federal jobs now closed to them here under a bill okayed by the House yesterday.

The legislation, by Rep. Bill Clay (D-Mo.), would also benefit thousands of job-hunters from West Virginia, Pennsylvania and North Carolina. They also are denied consideration for one of every seven federal jobs here because of a 90-year old law setting quotas for some government jobs based on state populations. All those states, and a few others, are either at or above their quota, and residents of them cannot legally be considered for some federal positions here - ranging from low-level to middle grade positions.

Congress passed the so-called apportionment law back in the 1880s, when merit was new to the government, in an attempt to spread federal jobs around to residents of all states. What seemed like a good idea at the time (probably was) has become an administrative nightmares for agencies, and a stumbling block for thousands of people who were denied consideration for federal employment in those quota positions simply because they came from the wrong place.

On the other hand, many places like American Samoa, Guam, Idaho and Nevada never have reached their quota, so the jobs are left vacant.

Virtually the entire metropolitan Washington area congressional delegation supported the apportionment repeal bill, which now goes to the Senate. The Carter Administration supports the legislation, and Senate approval, probably early next year, is expected.