Gen. Andres Rodriguez, who ousted strongman Alfredo Stroessner three months ago, was elected president by an overwhelming margin and his party kept control of congress, unofficial returns showed Tuesday.

The leaders and presidential candidates of four opposition parties charged the voting was fraudulent.Foreign observers and diplomats agreed there were irregularities, but said the balloting was reasonably fair and that victory clearly belonged to Rodriguez, who had been Stroessner's No. 2 man.

"We promise our people that we will carry Paraguay on a bright path to its destiny of greatness and happiness," a grinning Rodriguez said in a champagne toast to party members late Monday at his chateau-style mansion.

His Colorado Party has ruled this landlocked country of 4 million people since 1947.

Domingo Laino, the presidential candidate of the Authentic Radical Liberal Party and a former exile, finished second.

Only one of the four opposition candidates conceded defeat.

"In spite of the irregularities, I recognize that he won and that it was a landslide victory," said Fernando Vera of the Revolutionary Febrerista Party who finished fourth.

By midmorning, official returns showed Rodriguez with 131,075, or 75.24 percent, of the 174,201 votes for president; and the party with 114,247 or 66.21 percent, of the 172,560 votes for congress.