Washington — The Reagan administration appeared over the weekend to step back a little from its hard-line policy on Central America and move slightly more toward a negotiated way out of the turmoil there.
There were several straws in the wind:
* US Secretary of State Alexander Haig held talks Sunday with Mexican Foreign Minister Jorge Castaneda de la Rosa. Both afterward indicated a new US readiness to consider contacts with Cuba. Mr. Castaneda said he would be in touch with Cuba and Nicaragua in the near future about United States views on Mexico's peace proposals.
* Washington policymakers now are described as viewing Central America's turmoil as a global issue rather than simply a regional problem. Hence, the administration is understood to be considering talks with the Russians about the region.
* One spur toward this greater emphasis on talks could be the difficulty the Reagan administration is having in making its charges of Cuban and Soviet involvement in Central America stick. It was red faced at having a Nicaraguan guerrilla captured in El Salvador recant previous assertions of outside interference in El Salvador.
As if this were not enough, Nicaraguan official Jaime Wheelock Roman in a Washington press briefing put considerable doubt on at least one aspect of Washington's claim of a Nicaraguan arms buildup. Mr. Wheelock produced documents suggesting that airport expansion in his country was undertaken as part of a Central American bank loan given to former dictator Anastasio Somoza Debayle based on a US consulting firm's feasibility study.
None of this demolished the Reagan administration claims of an overall Nicaraguan military buildup and of Soviet and Cuban involvement in El Salvador. But it was, as one official put it, ''a case of having to wipe a lot of egg off our face.''
Washington's view that Central America's turmoil is not simply a regional, but rather a global concern is giving the small countries of the area a world prominence they never have had before.
''The region has become center stage,'' Mr. Wheelock commented last week in an interview. He asserted, however, that the US case for Soviet and Cuban involvement in the area is overdrawn. He specifically denied Nicaraguan involvement in El Salvador's civil war.
The administration is sticking to its claims, however, as it reportedly readies covert intelligence countermoves. Thomas O. Enders, the assistant secretary of state for inter-American affairs, is just back from Argentina and Chile and is rumored to have gained support from both countries for a joint covert response.
The Argentines, however, are understood to want to go further than Washington in dealing with the region. They reportedly seek the overthrow of the Sandinista government in Nicaragua and appear to be ready to include former Somoza national guardsmen. The US limits its effort to focusing outside attention on Cuban involvement.
Some US covert activities are rumored to be already under way and may have started as early as last November. This has prompted congressional moves to require the administration to obtain prior approval for any military or covert intelligence operations in Central America.
It was also disclosed last week that the administration has been giving aid for months to business, labor, and other civic groups in Nicaragua despite a freeze on US aid to that country since early last year.