The Senate Finance Committee yesterday kept a flicker of hope alive for national health insurance, refusing to shelve the bill for the remainder of the year.

Without a formal vote, the committee, at the urging of Chairman Russell B. Long (D-La.) and Sen. Abraham A. Ribicoff (D-Conn.), agreed to continue work on a bill that would require employers to provide employes with insurance against "catastrophic" medical costs and would beef up Medicaid coverage for the poor.

Ribicoff, conceding that the current push to cut the federal budget would make it almost impossible to pass a health insurance plan with large immediate costs, said he favored a moderate-cost package that could be phased in over a number of years, and then finding the money to pay for modest initial costs.

Although it was Republicans who earlier this week had suggested putting the bill aside because of budgetary constraints, senior Republican Bob Dole (Kan.) indicated he is willing to go forward to see if agreement can be reached on a bill. While passage this year might still be a long-shot possibility, Sen. Daniel P. Moynihan (D-N.Y.) said he saw no reason why the committee shouldn't go ahead with "a certain amount of postwar planning."