Boudou, appointed as economy minister in July 2009, has emerged as one of Fernandez’s most loyal cabinet ministers. In his previous job as head of the state pensions body, he won her trust when she nationalized private pension funds in 2008.

“He’s a person who’s been loyal to this president,” Fernandez said in a televised speech, praising Boudou’s stewardship of the economy.

Boudou is likely to have backing in different sectors of Fernandez’s support base, including the trade unions and younger members of her Peronist party who have risen to prominence in the past year.

Attention turned to the center-left leader’s choice of running mate on Tuesday when she ended months of speculation by confirming she would run for a second four-year term.

Fernandez, who easily won election in 2007, vows to extend the leftist policies that have infuriated many business leaders and farmers in Latin America’s No. 3 economy.

She has billed her candidacy as a tribute to her late husband and predecessor as president, Nestor Kirchner, whose death last year triggered an outpouring of public sympathy and boosted her popularity.