The House Education and Labor Committee approved a compromise bill yesterday that would require medium-size and large employers to give workers unpaid leave to care for newborn babies or to deal with the serious illness of a child, a parent or themselves.

The employers also would be required to maintain the worker's health benefits during the leave and to return the employe to the same or equivalent position at the end of the leave.

The committee passed the legislation 21 to 11 after rejecting some weakening amendments proposed by Republican members. The bill is opposed by the Reagan administration and business groups, which have argued that employers and workers should negotiate benefits rather than have Congress mandate them.

The measure probably will come up for a vote on the House floor early next year, a committee spokesman said.

The legislation, a more modest proposal than originally sought by House sponsors, would enable an employe to take up to 10 weeks of unpaid leave over a two-year period after the birth or adoption of a child. The same leave policy would apply if a parent or child were seriously ill. Employes may take up to 15 weeks of unpaid leave for their own serious illness.

The bill would apply to employers with 50 or more employes for the first three years, and then would apply to those with at least 35. The employe must have worked for the company for at least a year, and a company can refuse leave to the top 10 percent of its highest-paid workers if the employer can show a business necessity.

Rep. Margaret Roukema (R-N.J.) sponsored the compromise with Rep. William L. Clay (D-Mo.) in an attempt at a bipartisan measure, but the only other committee Republican to vote for the bill was Rep. James M. Jeffords (Vt.), the ranking minority member.