Omar BongoThe head of Gabon’s senate was sworn in Wednesday as the Central African nation’s interim president, the first time in more than four decades that anyone except the late leader Omar Bongo has held power.

Bongo died Monday at the age of 73 after suffering cardiac arrest at a Spanish hospital where he had been treated for weeks.

Senate chief Rose Francine Rogombe’s appointment to the interim presidency follows constitutional procedure and sets the stage for presidential elections she must organize within 45 days. By law, only a natural disaster or catastrophe could delay the poll date, by up to 45 more days, said constitutional court president Marie-Madeleine Mborantsuo.

Bongo’s body was expected to be flown back to Gabon on Thursday, and the government said he would be buried June 18 in Franceville, capital of his native province.

Known as one of Africa’s last “Big Men” — leaders who clung to power through fear and corruption — Bongo had dominated the oil-rich former French colony for 42 years. Both loved and feared, he was, at the time of his death, the world’s longest-serving president, the only leader most Gabonese ever knew.

In the wake of his death, the government has sought to reassure its population the country will not degenerate into violence without him.

Rogombe took the oath of office before the nine judges of the nation’s constitutional court, saying: “I swear to respect the constitution and serve the nation.”

The ceremony was held at an international conference center in the capital, Libreville, witnessed by nearly 1,000 people, including Cabinet ministers, lawmakers and diplomats.

The power vacuum leaves the forested nation of 1.5 million people at a crossroads, and many believe Bongo’s son, Defense Minister Ali Ben Bongo, is positioning himself for the presidency. On Monday, he went on national television to appeal for calm, but said he was speaking on behalf of his family.

Copyright 2009 The Associated Press.