Updated

Mario Abdo Benitez took over as Paraguay's new president on Wednesday, replacing a seemingly disgruntled Horacio Cartes, who left the inauguration ceremony before it finished.

Abdo Benitez, 46, promised to combat poverty and entrenched corruption, and urged Paraguayans to "look toward the future and not remain stuck in the past" as he took the oath of office to start a five-year term

The marketing expert campaigned to continue Cartes' business-friendly policies and played down fears of a return to the heavy-handed past of dictator Alfredo Stroessner, who ruled from 1954 to 1989. Abdo Benitez's father was Stroessner's private secretary.

While they belong to the same Colorado Party, Cartes has been unhappy that Abdo Benitez failed to back his effort to take an elected seat in the Senate. That would have given Cartes greater influence — and possibly immunity from any future efforts to prosecute the former soft-drink and tobacco magnate.

Paraguay's constitution says former presidents automatically become senators for life, with a voice but without a vote, and some say that means it's impossible for them to take an elected seat with greater powers.

Cartes and his allies felt "betrayed and humiliated" by Abdo Benitez and his allies, said Pedro Aliana of the Colorado Party.

"Cartes was generous with Ando Benitez by putting into practice unity and collaborating generously during the campaign that led him to win the vote on April 22," Aliana told reporters.

During the campaign trail, Abdo Benitez also vowed to improve the health system, develop alternative sources of energy and boost the agricultural sector which is the backbone of the economy. But he will need to strike alliances with members of other political parties to achieve major political and economic changes because he lacks a majority in both houses of Congress.

Paraguay is one of the poorest and most corrupt countries in Latin America. The corruption watchdog group Transparency International ranks it 135 out of 180 nations. But under Cartes, the economy, fueled by agricultural exports, has remained one of the strongest in the region.

The international Monetary fund expects Paraguay's economy to expand by 4.5 percent this year.