President Reagan is expected to name Donald I. Hovde, undersecretary of Housing and Urban Development, to the Federal Home Loan Bank Board, administration sources said yesterday.

Hovde, 52, a Madison, Wis., realtor and developer and former president of the National Association of Realtors, is said to have tired of his extensive traveling and administrative duties and wants to focus on the housing market.

Hovde would fill a vacancy on the three-member board after chairman Richard T. Pratt steps down later this month. The board's newest member, Edwin J. Gray, a savings and loan executive from San Diego, is expected to become chairman.

Hovde's departure from the No. 2 job at HUD would be part of a minor reorganization. Secretary Samuel R. Pierce Jr., despite a low political profile, has outlasted a spate of rumors that he may step down this year and now is looking to sharpen the agency's political skills in anticipation of next year's presidential campaign.

Administration sources say that former federal housing commissioner Philip D. Winn is a leading candidate for the undersecretary's job. Winn, 57, a Denver developer and homebuilder who left HUD early last year to make a losing Republican primary race for governor of Colorado, is highly regarded by the White House, which is considering him for a number of federal jobs.

Pierce also is creating the new post of assistant secretary for public affairs. Sources say that job will go to Robin Raborn, who has been a press spokesman for both the Office of Management and Budget and Merit Systems Protection Board. Leonard Burchman, who has been directing the 35-member HUD press office, will become deputy assistant secretary for public affairs.

Raborn, 30, a former marketing executive with Colgate-Palmolive Co., helped publicize the administration's campaign against fraud and abuse while at OMB. As a presidential appointee, she would not be bound by Hatch Act restrictions and free to make political speeches for the administration.