Egypt’s newly elected upper legislative chamber chose a member of the country’s most powerful Islamist group to lead it Tuesday, extending the control of parliament by the Muslim Brotherhood’s political wing.

The vote for the Freedom and Justice Party’s Ahmed Fahmy, a pharmacology professor, as speaker of the upper house followed the election of the party’s Mohammed Saad el-Katatny last month to lead the much more powerful lower house.

The Muslim Brotherhood is the nation’s oldest Islamist organization and since President Hosni Mubarak’s ouster last year, has become the nation’s most influential political force. Its Freedom and Justice Party emerged from recently concluded elections with just under half of the 508 seats in the lower house and almost 60 percent of the 180 seats in the upper house. Egypt’s ruling generals are supposed to appoint an additional 90 lawmakers to the lower house but are widely expected to leave that job to the nation’s first elected president, who will be chosen before the end of June.

Followers of a puritanical form of Islam known as Salafism took the second-largest number of seats in both houses as liberal and secular candidates floundered.

The two houses are expected to hold a joint meeting Saturday to begin the selection of a 100-member constituent assembly, the most important undertaking of the new parliament. The assembly will be tasked with writing a new constitution ahead of the presidential election.

The document will then be put to a referendum.