The search has begun for a new spiritual leader for the Reform movement's flagship congregation, the West London Synagogue, after this week's announcement of the impending retirement of Rabbi Mark Winer.

Earlier this year, congregants were informed that Rabbi Winer, 67, would be stepping down, but without a date being given.

But West London chairman Jonathan Lass ended speculation in a letter informing members that Rabbi Winer would retire next month on Succot.

"It has taken us several months to work out the details since Mark first indicated to us earlier this year that he would like to retire," Mr Lass explained. "Our highest priority was to ensure a smooth transition to a new senior rabbi."

He also announced the appointment of Simon Myers, UK chief finance officer of Swiss Bank Corp and UBS, as the synagogue's new executive director. The post was advertised at a £70,000 salary.

Mr Lass said that during Rabbi Winer's 12 years in charge, the synagogue had made "enormous strides" in its programming.

"Mark will best be remembered by most of us for making tikkun olam - repairing the world - a priority for West London Synagogue. Highlights included his two years as chaplain to two different Lord Mayors of Westminster, our seder in Parliament, many interfaith services in our synagogue and the unique strategic partnership between the synagogue, the Central Mosque and St Ethelburga's Centre for Peace and Reconciliation of the Church of England."

Utah-born Rabbi Winer, who served several American congregations before coming to London, was also renowned for his fundraising skills. It was a valued asset in a synagogue that was spending over £3 million, according to its 2007 accounts. Its highest-paid employee was then paid more than £140,000 annually.

But the economic downturn has forced the 170-year-old congregation to make job cuts over the past year.

After the death of Rabbi Hugo Gryn, he was chosen ahead of West London's then long-serving second-in-command, Rabbi Jacqueline Tabick, who left for North-West Surrey Reform Synagogue. Rabbi Winer was abroad this week and unavailable for comment.