An 18-month search for new global trade and financial policies ended inconclusively to early this morning as the North-South dialogue between industrial and developing nations sputtered to its finish.

Delegations representing 26 countries and the European Common Market did reach agreement on some limited points, most of which consisted of financial concessions by the industrial nations to the Third World in the form of commodity supports and emergency aid.

But neither side in the Conference in International Economic Cooperation, as the talks are formally known, came close to achieving the original and conflicting objectives each set for the conference.

The most significant failure was that of the industrial nations to get any movement on energy supplies or pricing from the Seven Organization of Petroleum Exporting Countries (OPEC) members, who formed the most important slice of the developing world group.

The long-term effect of the failure of the two groups to work out significant new forms of economic cooperation are still uncertain. But one immediate repercussion of the failure could come at the July 12 OPEC meeting on crude oil prices.

The oil-exporting nations have repeatedly said that the results of the North-South dialogue would affect their stand on new prices rises.

The eight delegations from the United States, Canada, Western Europe and Japan had sought to center the Paris talks on energy supplies and pricing and agreed only grudgingly when the conference opened in December, 1975, to expand it to include discussions of raw materials, development aid and finance.

The 19 countries of Latin America, Africa, Asia and the Middle East that formed the "South" had set as their target the formation of a new world economic order to replace the post-World War II sysytem reeling now under the impact of worldwide inflationary and unemployment cycles and crude oil prices increases.

Foreign ministers from the 27 countries gathered here Monday for what was scheduled as a formal and harmonious end to 18 months if technical negotiations on trade and aid.

But the energy issue provoked a final disruptive battle that brought a marathon negotiating session that began Wednesday afternoon, the original deadline for closing the conference, dragged on to 4 a.m. yesterday, resumed at mid-morning and then droned on after midnight into this morning before finally breaking up.

Secretary of State Cyrus Vance left early yesterday, and other foreign ministers filtered out of Paris during the day. The absence of French President Valery Giscard d-Estaing, who originaly proposed the conference and launched it ceremonially, at the closing session also emphasized lack-lustre finish to an ambitious project.

While noting that progress had been made, a joint communique issued at the conference's end also registered "regret" by both sides that they had not bridged their deep differences. The group of eight specified their disappointment over getting no agreement on energy.

American delegation members indicated that a "good faith" pledge to talk further about energy supplies to the West would be fair compensation for the financial concessions the Carter administration has conditionally agreed on making.

But a serious miscalculation by the United States and Saudi Arabia of the mood within the oil-producing countries contributed to the last minute impasse over energy, according to conference sources.

Saudi Arabia and Iran, the two largest oil producers in OPEC, agreed at the outset to an American proposal to include a committment to permanent consultations on energy in the conference's final communique.

But violent opposition to the proposal from Iraq, Venezuela and to a lesser extent Algeria produced a deadlock on the energy issue after the United States had already committed itself on trade issues.

The oil radicals were able to spike Vance's proposal to carry the North South dialogue beyond its terminal date on order to keep discussion going on energy. This in itself represented a shift in America policy, which previously has been to try to isolate discussion on energy with producers.

Vance suggested in speech Monday that American economic concessions depend on a "successful" conclusion to the conference. But he refused to specify any measures that would be used.

Sen. Jacob K. Javits (R.N.Y.) who is on the American delegation, told reporters yesterday that while the American pledges were not made on a quid pro quo adsis, some signs of a "good faith effort" by the developing countries were neede to help the Carter administration get approval from Congress for new aid.

Javits said he expected that North-South dialogue would continue with meetings on all topics covered here, except energy. But delegates from both industrial and developed countries said that while a general dialogue on trade and aid would be carried on in other forums, there would be no further formal North-South meetings.

Agreements made final here this week and listed in an annex published with the joint communique include:

A $1 billion emergency aid fund for the world's poorest countries. The United States has pledged $375 million, the nine Common Market countries will put up $385 million, and the rest will come from Spain, Sweden, Switzerland, Australia and Canada.

The financing of a common fund to support individuals agreements on half a dozen commodities. Operation of the fund, which could eventually reach $1 billion, according to some estimates, and identifying the commodities will be covered are to be negotiated through the Unted Nations Conference on Trade and Development in Geneva in November.

This represents significant movement by the United States on the principle of commodity price support funds. The agreement , however, falls far short of the kind widely based and automatic fund the group of 19 had originally demanded.

An increase in technical assistance to help African countries develop infrastructure, and a generalized commitment by the Western countries and Japan to increase their official aid, with a reference figure of 0.7 per cent of gross national product being mentioned.

Currently, the United States devotes a little less than 0.3 per cent of gross national product to foreign aid, according to the Organization for Economic Cooperation and Development.

Despite strong pressure from the 19 developing nations, no agreement was reached on declaring a general debt moratorium for the Third World. The industrial nations also turned back efforts to egt an economic index that would tie prices of raw materials to manufactured goods and inflation.