TRENTON (By David W. Chen, NYTimes) December 7, 2005 —  After months of speculation and aggressive campaigning by several candidates seeking the job, Governor-elect Jon S. Corzine of New Jersey has selected Robert Menendez of Hudson County to replace him in the United States Senate.

The decision is the first major one made by Mr. Corzine, a Democrat, since winning the governor's race last month. From the outset, Mr. Corzine said that he wanted to find the most qualified candidate who shared his liberal values, as well as someone who could win a tough and expensive statewide race - qualities that Mr. Menendez, who has already raised more than $4 million and won the support of national Hispanic groups, evidently brings to the table.

Representative Steven Rothman of Bergen County, who has advocated Mr. Menendez's appointment for nearly a year, said today that Mr. Menendez's selection "is the culmination of years of hard work on Bob's behalf and those who have supported him."

Two Democratic strategists, speaking on condition of anonymity so as not to overshadow the governor and Mr. Menendez, said that they had been briefed by Corzine aides that the appointment had become final by today, and that they expected a formal announcement of the congressman's selection, possibly on Thursday.

Mr. Menendez, 51, the son of Cuban immigrants who grew up in a tenement in Union City, is the third-highest ranking Democrat in United States House of Representatives and has long dreamed of serving in the Senate. He will serve out the one year that remains in Mr. Corzine's term and is widely expected to run for a full-six year term next November against Thomas H. Kean Jr., a Republican state senator and the namesake son of one New Jersey's most popular governors.