Bolivia's Congress has accepted the resignation of President Carlos Mesa.
Protests might die down after the latest developments
Supreme Court head Eduardo Rodriguez was sworn in as president, after Senate speaker Hormando Vaca Diez, who would normally take over, refused the job.
Protesters had halted a parliament session because they objected to Mr Vaca Diez, but it is now likely early elections will be called.
A miner was shot dead by the army earlier on Thursday, the first fatality in a month of protests.
Demonstrations began over President Mesa's handling of the country's gas reserves, with anger at the role of foreign companies and calls for nationalisation of the industry.
President Mesa said on Monday that he would step down, but protesters blockaded Thursday's parliament session, unhappy about Mr Vaca Diez, who as Senate leader automatically takes over, according to the constitution.
They see him as a representative of the business elite.
But late on Thursday, he indicated he would refuse the presidency.
"If the vote is to accept the president's resignation, Hormando Vaca Diez will decline," he said.
Some protesters tried to kick away police gas canisters
The next in line, the head of the lower house, had already said he would decline to succeed Mr Mesa - meaning that the presidency would pass to the head of the Supreme Court.
The BBC's Elliott Gotkine says Mr Rodriguez will now be obliged to call presidential elections - which would defuse the protests.
Trade union officials say the miner died in a clash with army troops near Sucre, where the Congress session is being held.
Coro Mayta, 52, a miner union leader, was shot dead by a soldier at a checkpoint in the village of Yotala, just outside Sucre.
He was on board a bus full of protesters. Two more people were wounded when the troops opened fire, news agency Reuters reported Interior Minister Saul Lara as saying.
The military claim the miners attacked the checkpoint by throwing sticks of dynamite.
It is the first fatality since protests began a month ago.
Clashes took place also inside Sucre after miners managed to enter the city despite a heavy deployment of security forces aimed at sealing it off.
Unrest has also continued in the main city of La Paz, where a strike shut the airport and road blocks cause shortages.
The chaos in La Paz prompted Congress to hold Thursday's session in Sucre, 600km south-east of La Paz.
The armed forces had appealed for calm and said they would respect Congress' decision on the presidency.
However, opposition leader and presidential hopeful Evo Morales warned earlier that bloodshed would follow if Congress conferred the presidency on Mr Vaca Diez.
Left-wing protesters want early elections, as well as nationalisation of the energy industry and constitutional reform.
The protests erupted last month after a law was passed imposing taxes on foreign companies that have invested in Bolivia's gas reserves, thought to be the second-largest in South America.
The protesters said the law did not go far enough and called for the gas industry to be nationalised.
They also want constitutional reforms to give greater rights to the country's impoverished highlanders, most of whom are of indigenous descent.
They oppose demands from Bolivia's resource-rich eastern provinces for greater autonomy and more foreign investment.
Mr Mesa came to power 19 months ago after his predecessor was forced out by similar protests over energy.
Mr Mesa offered to quit during similar protests in March, but the offer was rejected by Congress.