The Democratic-led House approved a $12.6 billion foreign-aid bill by voice vote yesterday, after Republicans pushed through a number of amendments designed to toughen U.S. posture toward leftist governments around the world.

Coupled with earlier Senate approval of its own aid bill, the House action on the fiscal 1986 measure means that the Congress is all but certain to enact a foreign-aid program for the first time since 1981. The two chambers must resolve their differences in a conference.

In the past several years, foreign-aid bills have been defeated in the Senate and have been approved only with great difficulty by the House because of widespread opposition by Republicans, many of whom view foreign aid as a giveaway program.

But yesterday, a number of Republicans rose to praise the bill before its adoption, citing the GOP-sponsored amendments adopted during the three-day debate. The most notable is the repeal of the decade-old Clark amendment barring U.S. military assistance to rebel groups fighting Angola's Marxist government.

Administration officials, while opposing the overall foreign-aid bill, said yesterday they were particularly pleased with the repeal of the Clark amendment because it appears to signal a shift in congressional attitude and ended what the White House saw as an infringement on presidential authority.

The amendment, named after former senator Dick Clark (D-Iowa), was adopted in 1976 after revelations of Central Intelligence Agency involvement in Angola's civil war. A senior administration official said yesterday the White House has no immediate plans to provide aid to Angolan rebels. The Senate also voted to repeal the Clark amendment, though on a different bill.

House Intelligence Committee Chairman Lee H. Hamilton (D-Ind.) said yesterday that repeal of the Clark amendment "should not be construed as an endorsement by Congress . . . for military or paramilitary operations in Angola. Whether or not we provide that assistance is a separate and future question."

Other GOP-supported amendments to the foreign-aid bill included a cutoff of all non-emergency economic aid to Mozambique's leftist government unless it kicks out most foreign military advisors and troops and authorization for House approval of $27 million in humanitarian aid for rebels fighting Nicaragua's leftist regime.

The House also voted to deny federal aid to private international organizations that perform or actively promote abortion and agreed to freeze funding for all foreign aid at the 1985 level.

"There were a number of significant changes in this foreign-aid bill" that made it palatable to Republicans, said House Minority Whip Trent Lott (R-Miss.). "That's about as good a foreign-aid authorization as they the Reagan Administration will ever get out of this House."

Administration officials said yesterday they continue to oppose the House bill, because it provides less than the $13.2 billion requested by Reagan; reduces military while increasing development aid, and contains some restrictions on presidential authority, including a ban on the sale of warplanes and other advanced weapons to Jordan unless it recognizes Israel.

Lawmakers said yesterday the House took a harder line in this year's foreign-aid bill because of anger caused by the recent hostage-taking in Lebanon and a sense that there has been a surge in terrorism against Americans around the world.

"People are just kind of knee-jerking," said liberal Rep. Howard E. Wolpe (D-Mich.). "There's a very edgy mood in the Congress, a very interventionist mood."

House Foreign Affairs Committee Chairman Dante B. Fascell (D-Fla.) said the measure passed because "there's something in there for everyone."

A number of liberal Democrats threatened to vote against the bill because they opposed the GOP amendments. In the end, they supported it because of other provisions, including substantial new aid to Israel and some restrictions on assistance to the Philippines and Latin American countries guilty of human-rights abuses.

The bill was adopted without the traditional roll call because neither liberal Democrats nor conservative Republicans wanted to be on record supporting it, even though they were willing to see it passed.

Other amendments approved included the addition of $5 million in aid to noncommunist rebels fighting the Vietnamese occupation of Cambodia and the cutoff of all but the humanitarian portion of $2.5 million in aid to Lebanon if seven American hostages there have not been released by enactment of the foreign-aid bill; and permission for U.S aid to be used to train civilian police forces in El Salvador and Honduras.

The legislation authorizes $12.6 billion for foreign aid in both 1986 and 1987.

Israel and Egypt would get more assistance than other countries. Under the bill, Israel is authorized to receive $3 billion next year and in 1987 and Egypt $2.1 billion. An additional $1.5 billion in emergency economic assistance this year was also earmarked for Israel.