Polls in Bolivia have closed and voters awaited the results of a presidential runoff that marks a decisive rejection of the socialist government and a likely foreign policy shift toward the United States after decades of frosty relations.

Initial results are expected after 12pm AEDT.

The race pits centrist Senator Rodrigo Paz against conservative former president Jorge "Tuto" Quiroga. Both candidates have pledged to strengthen diplomatic ties with Washington - strained since 2009 - and seek US-backed financial support to stabilise Bolivia's fragile economy.

The runoff between two pro-market candidates from privileged backgrounds signals an epochal shift for Bolivia, following two decades of dominance by the leftist Movement to Socialism party, founded by Evo Morales and once backed by t

See Full Page