Secretary of State Hillary Rodham Clinton has chosen a new special envoy to Afghanistan and Pakistan, after months of delay and disagreements between the White House and the State Department over the parameters of the job that became vacant with the December death of Richard C. Holbrooke, senior officials said.

Retired diplomat Marc Grossman is expected to take over as the administration is facing a crucial year for its war strategy in Afghanistan, where it plans to begin U.S. troop withdrawals this summer and to move toward a political settlement including negotiations with the Taliban before the end of 2011.

In Pakistan, a key partner in the strategy, the situation has become even more fraught with peril, as U.S.-Pakistani relations have plummeted to their lowest point in years over Pakistan's rejection of U.S. demands to grant diplomatic immunity to a U.S. official accused of murder there.

The administration has suspended high-level official contacts with the Pakistanis, and senior members of Congress have warned Islamabad that it risks a cutoff of U.S. aid.

Clinton, who met with Grossman Monday morning at the State Department, expects to announce his appointment in a major Afghan-Pakistan speech she will deliver at the Asia Society in New York Friday, if not before, administration officials said. The officials spoke on condition of anonymity, saying they could not discuss the appointment on the record until it was announced.

Asked about the planned appointment, Grossman said he was "not in a position to comment."

In a nearly three-decade career at the State Department, Grossman served as assistant secretary of state for Europe and ambassador to Turkey. His last assignment, before retiring from the foreign service in 2005, was undersecretary for political affairs during the first administration of George W. Bush.

He now is vice chairman of the Cohen Group, which advises international business clients on overseas enterprises. Although the consulting group, headed by former defense secretary William Cohen, has several clients with contracts in South Asia, administration officials said they did not foresee any problem in clearing Grossman for the post.

Clinton said in the days following Holbrooke's sudden death from a torn aorta that she intended to keep the office intact in terms of personnel and mission. She has frequently cited the "AfPak" special representative as the leading example of the "whole of government" approach she has set for administration foreign policy.

Holbrooke brought representatives from departments across the administration, along with outside experts, onto his team. Its mandate is to coordinate all civilian aspects of the strategy and serve as an equal counterpart to the military.

But Holbrooke frequently ran afoul of the White House, where some officials disapproved of the breadth of his activities that extended from congressional liaison to negotiator with foreign governments, and senior administration representative to Afghan and Pakistani leaders, all the way to visits to obscure Afghanistan aid programs and Pakistani refugee camps.

According to one candidate who discussed the job with Clinton, she was looking for someone with the stature to speak for both her and President Obama to Congress and foreign governments. Some in the White House, this person said, wanted someone with a more traditional diplomatic background whose duties would be restricted to representing the administration in the region.