WASHINGTON (AFP) - Senate Republicans on Thursday unanimously elected Mitch McConnell as their chief and the chamber's majority leader for the upcoming Congress, after the party rode to victory in last week's midterm elections.

As expected, McConnell will take over from current Senate Majority Leader Harry Reid at the start of the new congressional session on Jan 3.

Reid, a Democrat, has held the post since his party won the Senate eight years ago.

McConnell spokesman Donald Stewart said the vote took place behind closed doors in the US Capitol.

The 72-year-old Kentuckian was re-elected to a six-year Senate term on Nov 4, when Republicans routed Democrats and seized the Senate majority, along with tightening their grip on the House of Representatives.

Reid, 74, was expected to be re-elected Thursday to head Senate Democrats, albeit in the role of minority leader.

Reid, as majority leader, will control the legislative agenda of the 100-member Senate in coordination with the top Republican in Congress' lower chamber, House Speaker John Boehner.