Newly elected Speaker of the US House of Representatives Paul Ryan is sworn in to succeed outgoing Speaker John Boehner on Capitol Hill in Washington October 29, 2015. [Photo/Agencies]

Ryan's main Republican challenger, Representative Daniel Webster of Florida, received nine votes from members of the right-wing Freedom Caucus and other conservatives who frequently battled with Boehner by pressing for quicker progress in shrinking government.

But most Freedom Caucus members, including chairman Jim Jordan, voted for Ryan. One vote each went to former Secretary of State Colin Powell, Representative Jim Cooper of Tennessee, and Representative John Lewis of Georgia.

Ryan now moves to the number two succession spot for the presidency behind the vice-president, a position he sought in the 2012 election as Mitt Romney's running mate.

Previously the chairman of the House Ways and Means Committee, Ryan has served in Congress since 1999. He is the architect of conservative budget plans that sought to slash social safety net programs, including effectively privatizing Medicare health benefits for seniors, while cutting tax rates for the wealthy and boosting military spending.

As the 54th speaker, Ryan's first challenge will be to avoid a government shutdown on Dec 11 when funds for an array of federal agencies expire.

Boehner, in an emotional farewell speech before the vote, said: "I leave with no regrets or burdens." In what could be a warning to hard-liners, Boehner advised: "Real change takes time ... So believe in the long, slow struggle."