Two top Ford Motor Co executives who helped steer the U.S. automaker through the financial crisis will retire by April 1, thinning the ranks of potential candidates who could replace Chief Executive Alan Mulally in coming years.

Chief Financial Officer Lewis Booth, 63, will be replaced by the company Vice President and Controller Bob Shanks, 59. Derrick Kuzak, 60, Ford's product development chief, will be succeeded by Raj Nair, 47, now the head of engineering for global product development.

Ford's board of directors met Wednesday and approved the plans. Separately, Ford announced that former U.S. Ambassador to China and one-time Republican presidential candidate Jon Huntsman will join the board.

The moves put the focus on Mark Fields, 51, who runs Ford's operations in North and South America, and Joe Hinrichs, 45, who runs the automaker's operations in Asia, as the leading internal candidates to succeed Mulally.

Lewis and Derrick are two exceptional, experienced leaders and we're so pleased to see them at this point be able to retire following tremendous careers at Ford, Mulally told reporters. They have created such a sound foundation for us to continue to profitably grow.

During a call with reporters, Mulally sidestepped questions on the future CEO, saying that he had no plans to retire and Ford had a very strong succession plan for every position, including my own.

Gary Bradshaw, portfolio manager at Hodges Capital Management in Dallas, which owns Ford shares, said he's confident Ford has its CEO succession plan in order.

They've got a good, deep bench there in my opinion. I think it is seamless. Nothing really will change, Bradshaw said.

Both Booth and Kuzak have been with Ford for more than 30 years and rose to their positions after Mulally became Ford's chief executive in the fall of 2006.

Booth became CFO in 2008, a week after the collapse of Lehman Brothers investment bank. Kuzak has led Ford's product development since December 2006. Both executives played key roles in Mulally's One Ford plan.

The plan, which has been a centerpiece of Ford's turnaround since 2006, calls for Ford to unify its once-disconnected business units and take advantage of its scale to drive down costs and build a global brand.

Mulally cited Booth's contributions to straighten out Ford's balance sheet and reinstate the dividend after helping the company through the rocky financial times after it mortgaged assets.

Ford's strategy helped keep it from filing for bankruptcy and a government bailout in 2009 as did its U.S. competitors General Motors and Chrysler.

The British-born Booth steered the automaker's sale of Swedish luxury brand Volvo to Chinese automaker Geely and was credited with bringing a more collaborative approach to a Ford leadership team that had sometimes been split by in-fighting, people with knowledge of Ford's operations have said.

During Booth's tenure, Ford cut debt, restored its dividend and began to eliminate risks associated with its pension plan.

In a sign of confidence in its turnaround, Ford made an accounting change last month that signaled that it expected to make profits in the future.

Kuzak was charged with launching a series of globally developed and designed vehicles that left Ford with more new models when its U.S. competitors had thinner new offerings. Kuzak ushered in the global versions of the sedans Fiesta, Focus and most recently the Fusion.

Recently, Ford announced that by 2013 it will have 85 percent of its global models on nine underpinning platforms.

(Corrects Fields' age to 51 from 50, paragraph 4)

(Reporting By Deepa Seetharaman and Bernie Woodall, editing by Dave Zimmerman)