Black African states are showing an unexpected degree of solidarity so far in rejecting the new black-led government in Zimbabwe-Rhodesia.

Except for Gabon and Zaire, no black African state has indicated any disposition to approve the lifting of sanctions against Zimbabwe-Rhodesia or to recognize the government of Prime Minister Abel Muzorewa.

The newly elected Conservative government in Britain has hinted strongly that it might recognize the Muzorewa government and the U.S. Congress may turn out to have a majority in favor of lifting economic sanctions.

But while debate rages in Congress over these issues, there has been remarkably little controversy in Africa.

Rather, there seems to be a broad consensus bridging the usual moderate-radical split in African politics that no settlement in Rhodesia can be legitimate until the rebel Patriotic Front leaders are brought into it.

Moderate black African states usually tagged "pro-Western" have almost all turned their backs on Muzorewa's entreaties for recognition. Some are warning Washington and London to beware of what they do lest they find themselves at odds with the entire continent over the Rhodesian issue.

Muzorewa has claimed that the special envoys he has dispatched since the April elections were "sympathetically" received in nine black African captials. If this is so, he has nothing to show for it so far in his desperate battle for recognition.

One unconfirmed report reaching here recently said Muzorewa's delegation sent to the Ivory Coast, one of Africa's most conservative states, was not even allowed beyond the airport to make its case to President Felix Houphouet-Boigny.

In Salisbury, government officials insist latent support exists in a dozen African and Arab countries for the internal settlement that has brought Muzorewa to power. But they say none dares to take the lead in extending recognition and all are waiting for London and Washington to act first.

African diplomats here, however, disagree. They say that a number of moderate or conservative African leaders such as Houphouet-Boigny who got caught on the losing side during the 1975-76 Angolan civil war are being extremely cautious toward the war in Rhodesia.

The attitude of Kenyan leader Daniel Arap Moi is indicative of the caution moderate black African leaders are demonstrating these days.

On a state visit in Britain last week, Moi told Prime Minister Margaret Thatcher that Kenya rejected the new constitution of Zimbabwe-Rhodesia "because it does not provide for real majority rule."

He called for renewed international efforts to bring Muzorewa and the guerrilla leaders together to work out a "permanent solution" to the war and political wrangle in Rhodesia.

Liberian President William Tolbert has also come out against the Muzorewa government, according to press reports. In a cable to Rep. Stephen Solarz (D-N.Y.), chairman of the House African affairs subcommittee, he warned Washington that the lifting of sanctions and recognition of the present Salisbury government "would adversely affect whatever support the United States may hope to garner among African states in respect of its inititives in the Middle East."

Another moderate West African state, Ghana, firmly rejected the Muzorewa government in a joint communique with Nigeria at the end of May. This is significant since Ghana provided Muzorewa with legal expertise during the 1976 Geneva conference on Rhodesia and was also reported to have paid some of his delegation's hotel bills there.

Meanwhile, Senegal, a leader along with the Ivory Coast of the French speaking African nations, has made its sympathies clear recently by agreeing to allow the Patriotic Front to open an office in Dakar. A Patriotic Front representative is about to leave Lusaka for the Senegalese capital, according to nationalist sources here.

The most surprising negative response to the Muzorewa government's plea for recognition has come from nearby Malawi, which had close relations with the white Rhodesian government and openly flouted the economic sanctions imposed by the United Nations 13 years ago.

On June 6, Malawi House in Salisbury was closed to signal President Hastings Banda's decision to take his distance from Muzorewa. The office, which had no diplomatitc status, had been in operation since 1938 primarily to look after the interests of the 250,000 Malawi workers in Rhodesia.

The reasons for Banda's action are still not clear, given his overall foreign policy of being the sole black African country to have diplomatic relations with either South Africa or Israel. But reports reaching here say Banda is trying to end Malawi's semioutcast status within the Organization of African Unity and also has come under considerable pressure from all neighboring black African leaders.

The two African countries most likely to break ranks eventually and recognize the Muzorewa government, according to Western diplomatic sources here, are Zaire and Gabon. Both have long traded secretly with Rhodesia despite U.N. sanctions and Zaire exports nearly half its copper exports through Rhodesia and South Africa.

Gabon is the only black African country that has publicly indicated it would be ready to recognize the new government in Salisbury provided Britain does, but not before.

Western diplomats here doubt, hoever, that Zaire or Gabon will move in the direction of recognition before the mid-July summit of the OAU, which seems certain to condemn the April elections, the new constitution of Zimbabwe-Rhodesia and the Muzorewa government as insufficient and call for a wider settlement including the Patriotic Front.