President Reagan, seeking to keep U.N. Ambassador Jeane J. Kirkpatrick in his administration, may ask her to take the job of revitalizing the International Development Cooperation Agency, which was intended to manage all U.S. foreign-aid activities but has been moribund since Reagan took office.

Well-placed administration sources had said earlier this week that Reagan planned to offer Kirkpatrick the post of administrator of the Agency for International Development, which was supposed to be subordinate to the IDCA when it was established in 1979.

Administration sources said that making Kirkpatrick head of a revived IDCA is among options that Reagan tentatively plans to discuss with her when they meet Wednesday at the White House to decide whether she will stay in the administration.

The sources said that, if Kirkpatrick shows interest, the scope and authority of the job would have to be arranged in further discussion.

Yesterday, some sources said problems arose over the AID job because the White House has received strong indications that Kirkpatrick would not accept it. As a result, the sources said, Reagan, anxious to placate conservatives who want him to retain her, is considering whether she might be attracted to head a restructured aid program with higher rank and broader authority.

The general idea, they added, would be to make Kirkpatrick what some called a "foreign-aid czar," with policy control over AID and several other agencies and programs charged with dispensing about $3 billion a year in nonmilitary foreign assistance.

These sources also said that premature disclosure of the possible AID offer had embarrassed the White House because AID Adminstrator M. Peter McPherson had not been told that he might have to make way for Kirkpatrick. That prompted White House spokesman Larry Speakes to tell reporters Thursday that Reagan has "total confidence" in McPherson.

As a result, the sources said, the IDCA plan under consideration would help the administration out of a bind. It would give Kirkpatrick a more enhanced position and permit McPherson to remain at AID. Kirkpatrick would be his boss.

The IDCA, created by President Jimmy Carter, was designed to direct and coordinate activities of AID, which administers direct assistance to individual developing countries; the Overseas Private Investment Corp., which insures U.S. private investment in such nations, and the Trade and Development Program, which seeks to stimulate these activities in the Third World.

In its first year, the agency showed signs of moving the aid program away from the policy dominance traditionally asserted by the State and Treasury departments and becoming an important independent force in U.S. foreign policy.

However, when Reagan took office in 1981, his administration tended to regard the IDCA as an unnecessary layer of bureaucracy, and it fell into disuse. For the last four years, the agency has existed only on paper and has not had an administrator. McPherson has held the title on an acting basis.

It would be a startling about-face if the administration were to try breathing new life into the IDCA.

The sources even reported talk of enhancing its potential attractiveness to Kirkpatrick by adding such powers as authority over the U.S. representatives at the World Bank and other multilateral lending institutions. One senior source said Kirkpatrick might even retain the right to attend Cabinet meetings.

Nevertheless, sources close to Kirkpatrick said they believe that she is unlikely to accept such a position. They said she would view it as a step down from the Cabinet rank and high visibility of the U.N. post and an erosion of her influence.