UNITED NATIONS – Secretary-General Annan plans to announce today that the head of the United Nations development program, Mark Malloch Brown, will become his chief of staff, according to sources in the organization.

Mr. Malloch Brown, 51, will continue to hold his current position as UNDP administrator in addition to his new post, an official who asked not to be named told The New York Sun. This will make him one of the most powerful officials at the organization. As chief of staff, or chef de cabinet as the position is known in Turtle Bay parlance, he would be responsible for most goings-on at the U.N.

The British Mr. Malloch Brown will replace Iqbal Riza, who announced his retirement December 22 amid a barrage of accusations against Mr. Annan from legislators in Washington, the American press, and – perhaps even more ominous for the embattled U.N. – the organization’s own staff.

The Sun’s front-page editorial calling for Mr. Annan’s resignation, as well as its disclosure that Mr. Annan’s son, Kojo, was on the payroll of a company involved in the oil-for-food program much longer than had previously been reported, began an avalanche that many at the U.N. were concerned could lead to a trend of long-term chilly relations with Washington.

The Pakistani Mr. Riza, 70, said his retirement was mostly due to age, but several sources told the Sun at the time that Washington’s pressure to “clean house” was behind his abrupt retirement.

Beyond scandals such as, most notably, oil-for-food, Washington was concerned about an increasingly ineffective U.N., which President Bush has warned might become “irrelevant,” as well as a drift to anti-Americanism and specifically a perception that Mr. Annan did not support Mr. Bush’s re-election efforts.

In addition, the New York Times reported in today’s edition that several friends of Mr. Annan and the U.N recently met in the Manhattan apartment of Richard Holbrooke, the former American ambassador to the U.N., in what one of them described as an attempt “to save Kofi and rescue the U.N.,” according to the Times, which first reported on Mr. Malloch Brown’s appointment.

Participants like Harvard’s John Ruggie, Leslie Gelb, the former Council of Foreign Relations president, Robert Orr, Mr. Annan’s aide, and Jeremy Greenstock, the former British U.N. ambassador, tried to impress on Mr. Annan that the U.N. cannot succeed “if it is in open dispute and constant friction” with America, Mr. Holbrooke told the Times.

Once Mr. Riza left, Mr. Annan was said by several confidantes to consider bringing in a high power person from outside the organization, which would infuse “new blood” into the system, a U.N. source told the Sun. Several former Asian officials were mentioned in that context. Asia is the major contender to fill Mr. Annan’s shoes after his scheduled departure in two years.

Apparently Mr. Annan has finally settled on his pattern of promoting staffers from within the U.N., with Mr. Malloch Brown, one of the rising stars at the organization, who has enough credentials in his pre-U.N. career to be considered a reformer.

Mr. Malloch Brown has been at the forefront of reorganization at the UNDP, which he has headed since July 1999, including what some of his aides called a “huge staff turnover.” One official said yesterday that “meritocracy” is a word often used at UNDP. This would bode well among those who have called for U.N. reform, the official hoped.

As a former World Bank official and a journalist who has covered Washington for the British weekly the Economist, Mr. Malloch Brown would probably be more versed in Washington sensibilities than his predecessor, as well as several others in Mr. Annan’s inner circle.

Mr. Riza’s announcement came immediately after Mr. Annan’s visit to Washington, where he met Mr. Bush’s nominee to head the State Department, Condoleezza Rice. Several diplomats said at the time that the Washington visit, and specifically the meeting with Ms. Rice, has been behind a shakeup inside the organization, which included the resignation of several top officials dealing with staff issues.

One of Mr. Malloch Brown’s aides has recently said he is mostly interested in restructuring the U.N., applying several ideas that were suggested in a recent high-level report by “eminent persons,” including raising the U.N.’s role in international crises, like the current one in Asia, but also long-term strokes, he added, like reducing national poverty by increased investment in poorer economies.