(Reuters) - An Egyptian parliamentary delegation including top Muslim Brotherhood figures will head to Saudi Arabia seeking to resolve the worst in crisis in decades between states that were close allies under deposed leader Hosni Mubarak.

The speakers of the upper and lower house of parliament, both senior members of the Brotherhood, will be in the delegation that the state news agency said would meet the Saudi king on Thursday over the crisis triggered by Riyadh´s arrest of an Egyptian lawyer and a wave of protests that it generated.

It marks a rare visit to the kingdom by members of an influential Islamist movement whose rise to prominence since Mubarak´s overthrow is causing concern in the conservative monarchies of the Gulf, analysts say.

A spokesman for the Brotherhood said it had been "a long time" since any member of the group had been to Saudi Arabia in an official capacity, but added they were going as representatives of parliament, not the movement.

Saudi Arabia withdrew its ambassador from Egypt at the weekend and closed its missions in the country of 80 million, citing security concerns following the demonstrations over Ahmed el-Gezawi´s detention.

The Saudi government has been the focus of public anger triggered by the arrest, with Egyptians pouring criticism on what they say is the poor treatment their compatriots often receive in the kingdom.

Egyptian activists said Gezawi had been detained for speaking out against such ill-treatment. The Saudi authorities said he had been smuggling drugs.

Analysts say the crisis is partly rooted in Saudi concerns over the growing influence of the Brotherhood, an Islamist movement founded in Egypt and which has offshoots all over the Arab world.

Mubarak, who was swept from power by a mass uprising last year, maintained an official ban on the group.

The parliamentary delegation would meet Saudi King Abdullah and other officials, the state news agency MENA said.

"The delegation will focus on affirming the depth of the historical and brotherly ties between the two countries ... and the need to work to remove any misunderstanding," MENA quoted Ali Fath el-Bab, who heads the Brotherhood majority bloc in the upper chamber, as saying.

The delegation would also discuss "the conditions and problems of Egyptians in the kingdom in a framework that preserves the dignity of Egyptians", he said.

The Brotherhood won nearly half the seats in parliamentary elections that were Egypt´s most democratic in more than six decades. But it says Riyadh has kept them at arm´s length: neither inviting its leaders to the kingdom or taking up the group´s invitations to meet them in Cairo. (Writing by Tom Perry Editing by Maria Golovnina) (© Thomson Reuters 2012. 05/02/12)