In the midst of slashing other federal programs according to the president's spartan plans, Congress has turned back an attempt by the Reagan administration to kill the tiny National Consumer Cooperative Bank. r

The budget reconciliation bill approved by Congress last week included a compromise -- negotiated in the final hours of the conference deliberations -- for turning the bank into a private entity several years earlier than planned, by the end of this year.

The quasi-government institution opened its doors in March 1980 to make loans to nonprofit consumer cooperatives, which claimed they could not get adequate funding from conventional bvanks.

It was supposed to get five years of federal funding -- all to be repaid over time -- but one year after it started operations the Reagan administration wanted to kill it, citing budget reasons and philosophical objections to such rederally supported lending. This started a fierce battle for survival by the tiny bank and its friends on Capitol Hill.

It eventuall yw as saved by an unusual bipartisan group led by House Banking Chairman Fernand St Germain (D-R.I.) and Rep. Chalmers Wylie (R-Ohio). Wylie and 17 other Republicans went so far as to tell the House Republican leadership they would not vote for reconciliation without an accommodation for the bank.

The compromise apparently changes the bank's funding more in form than i nsubstance from the way it originally was planned, but the bank will be smaller than it was supposed to be when it goes into the private markets.

A major part of the plan's political appeal si tht it takes the bank off the federal budget and ot of government control.

Originally, the Treasury was to buy up to $300 million in the cooperative bank's stock through fiscal 1983 to provide up-front seed money for the bank to lend to consumer cooperatives, which also would own stock in the bank. After 1983 the cooperative bank was to buy back its stock from the Treasury gradually, while selling stock on the private markets to raise more funds for loans.

Under the budget compromise, the bank by the end of this year will exchange the Treasury-owned stocks for debt instruments or notes, to be paid off fully by which the bank was to have bought back all its Treasury stock.

Within the next 18 months, the bank is to go to the private markets for additional funding.

The bank will ave less than the $300 million in federal up-front backing when it goes private, however. It currently has about $137 million in assets. The House has approved another $58 million in fiscal 1982 funding, but the Senate has deleted all money for the bank in the next fiscal year.

Officials of the cooperative bank and the Cooperative League of the U.S.A. said they were pleased with the compromise and that it would have the advantage of freeing the bank from government strictures.

"The bank has been pushed into the [private] markets much earlier than anticipated and at a much lower base than anticipated and at a much lower base than anticipated," a House Banking Committee staff aide said. "But it is nw free from having to worry about the next political decision."