President Reagan said yesterday that he will provide another $176 million in emergency food aid to Africa and will ask Congress for $235 million more to bring the U.S. famine relief commitment in fiscal 1985 to more than $1 billion.

U.S. Agency for International Development Administrator M. Peter McPherson said the total, if provided, would feed 10 million people in eight countries for 10 months with 1.5 million tons of food, about half the estimated need on the drought-ravaged continent. He challenged other nations to come up with the other half and reiterated his proposal for a world conference of donor nations to organize it.

In a statement, Reagan also announced a "Food for Progress" program that would give future U.S. food aid to countries that have shown "commitment to agricultural policy reform."

The program, to be detailed in proposed legislation later this month, would reward nations for establishing better prices to farmers, improved rural facilities for transport and production, and more private-sector involvement, Reagan said. "Poor countries must become more productive in agriculture if they are to grow the food so needed to feed their people," he said.

The Reagan administration has criticized the Marxist government of Ethiopia for moving slowly to deal with its famine, for collectivist agricultural policies that allegedly worsened the situation and for spending funds unnecessarily on its anniversary celebration and now on relocating about 1.5 million peasants to more fertile land in the south.

Ethiopia has said world reaction to its crisis has been slow, inadequate and tied with political strings that constitute intervention in its domestic affairs.

McPherson said AID and private voluntary groups are being "extremely careful" that U.S. food aid goes to hungry people and not to feed Ethiopian soldiers. He has accused the government of trying to starve out rebels in northern areas worst hit by the famine.

He said the $176 million in new U.S. aid would require no congressional action and would include $45 million diverted from other aid programs. Congress will be asked for $235 million more, of which $50 million will be spent to process and transport U.S. grain reserves to Ethiopia, Sudan, Kenya, Mozambique, Chad, Niger, Mauritania and Mali, he said. The United States has committed $590 million in emergency assistance, he said, and has also provided $750 million in "regular" economic aid to the continent.

The International Red Cross estimated in November that 300,000 people had died of hunger in Africa since last March, and relief workers say that at least 200 people die every day in Ethiopia. Although Ethiopia is the worst hit, with about 8 million hungry people, the United Nations says 14 million people in 28 African nations face famine this year.

Meanwhile, a group of 68 members of Congress, all but two of them Democrats, yesterday proposed a $1 billion appropriation for African famine relief. Rep. Ted Weiss (D-N.Y.), a member of the House Foreign Affairs Committee, criticized Reagan's proposal as belated, inadequate and largely made up of previously committed funds.

The congressional measure would provide $787 million in immediate relief, with the rest for longterm agricultural development.