Egypt's veteran politician Saad al-Katatni has been named as the new leader of the Muslim Brotherhood's political party.

Katatni was elected on Friday, replacing Mohamed Morsi, who became Egypt's president in June, as the head of the Freedom and Justice party.

"I am indebted for this trust," Katatni said in a speech after the result was announced.

"Egypt is waiting for us, the Freedom and Justice Party, to lead the political scene," Katatni said while accepting the post in the country's largest political party.

The 61-year-old microbiologist joined the Muslim Brotherhood in 1979. Katatni is seen as more conservative than Essam el-Erian, his main challenger for the post.

He was speaker of the first parliament after a popular uprising toppled Hosni Mubarak. The assembly, which was dissolved by Morsi, was dominated by the Brotherhood's FJP and Salafis.

Katatni took 67 per cent of 866 votes by members of the FJP's general committee, or executive.

Analysts expect no major policy change within the well-organised group, saying it was Katatni's calm, consensual stance within the movement that won him the leadership vote.

He said the role of the FJP, and its 400,000 members, was to "implement righteous rule based on Islamic sharia laws".