A Department of Agriculture official proposed in a memo last week that the agency take the lead in stripping federal regulations of civil rights guidelines that are "contrary to the administration's direction," including goals for hiring minorities.

The memorandum from Isidoro Rodriguez, director of the Office of Minority Affairs, said that the Agriculture Department is "receiving support and guidance from the Justice Department" to start the project and that the changes would prompt revisions in civil rights laws for the entire government.

But John Franke, deputy assistant secretary for administration, said in an interview yesterday that he told Rodriguez this week not to proceed and that the department "fully supports" civil rights laws and regulations.

Questioned about the memo during his news conference last night, President Reagan said he was unaware of it but "will look into it and communicate with Jack Block right away"--a reference to Agriculture Secretary John R. Block.

The memo mentions past policy statements by William Bradford Reynolds, assistant attorney general for civil rights, and suggests that Rodriguez was following his lead in redrafting regulations. Reynolds did not respond to telephone inquiries last night.

In his Feb. 8 memo, Rodriguez said:

"The rationale for the department taking the lead is that USDA is second in size only to the Department of Defense, and more importantly, it deals almost exclusively with domestic economic concerns . . . . For these reasons policy change in the department would have greater impact and would be less politically criticized than a policy change in any other department dealing strictly with social programs.

"Once the department has isssued its regulations, the Department of Justice will use them as a benchmark for other agencies within the executive branch."

Rodriguez also said Block "would obtain a great deal of positive attention by taking the leadership in civil rights."

Rodriguez wrote that the regulations were being redrafted with two major guidelines in mind: to reduce paperwork required of program recipients and to insure that regulations are "purged of any reverse-discrimination aspects (i.e., quotas, guidelines and underrepresentation)."

To justify his proposal, Rodriguez wrote that the "Republican Party as a whole and in particular the Reagan administration has not been supported by those ethnic/women's groups which have financially and politically profited by past civil rights policies."

He said 95 percent of the black population did not support Reagan and more than 60 percent of Hispanics voted against him, while "non-ethnic groups which have not received special benefits are making it clear in a number of ways that they are tired of ethnic favoritism."

Rodriguez, a political appointee, told a reporter yesterday he had received a letter Tuesday from Franke telling him not to proceed with the plan.

In the letter, dated Monday, Franke said that as the department's principal adviser on equal employment opportunities and civil rights it is his job to develop policy in compliance with current laws and added: "The USDA fully supports the civil rights laws, regulations ...."

Franke said in an interview yesterday that Rodriguez' suggestions were "offshoots" and "interpretations" of civil rights policy laid out by the administration. He said the memo was "an initiative or a view that was curtailed here" and never reached Block.

Before he was stopped, Rodriguez said yesterday, he was revising regulations in accordance with his memo. One proposal would have categorized women as a minority along with ethnic and racial groups, ending a separate "gender" category for women. The effect would have been to eliminate special programs for women and spread benefits for racial and ethnic minorities among more people.

According to sources, the department's record of evaluating programs and conducting field reviews for evidence of discriminatory practices has declined sharply since Rodriguez took office last June. For example, they said, investigations of program complaints fell from 90 in 1981 to none under Rodriguez. Compliance field reviews dropped from 92 in 1981 to one after Rodriguez took control, they added.

"The numbers have gone down," Rodriguez acknowledged yesterday, "but I would argue we have more impact now...."