Former Energy Secretary Felipe Calderon secured the presidential nomination for the ruling National Action Party, all but finalizing the major-party lineup for next July's historic presidential election, party officials confirmed Sunday. Mexican law prevents President Vicente Fox from seeking a second term, and a surprisingly bitter primary election developed as three former members of Fox's cabinet fought for the nomination of their center-right party. Calderon coasted to victory Sunday, winning about 58 percent of the vote in the third of three regional votes. The win gave Calderon about 52 percent of the cumulative vote - enough to avoid a runoff. Former Interior Secretary Santiago Creel publicly conceded defeat, having won about 33 percent of the cumulative vote. Alberto Cardenas, former environment secretary, captured about 15 percent overall. The primary battle led to increasingly sharp confrontations in a center-right party more noted for genteel, back-room negotiations.