* Santos names current energy minister Cardenas as finmin
* Cardenas will also be central bank board member
* More cabinet changes are expected in coming days
* Colombia economy is showing signs of moderation
By Jack Kimball and Helen Murphy
BOGOTA, Aug 23 (Reuters) - Colombian President Juan Manuel Santos moved Energy Minister Mauricio Cardenas to head the finance post on Thursday in a surprise move for Latin America’s fourth-largest economy.
At the midpoint of his four-year term, Santos asked all 16 ministers to resign, including Finance Minister Juan Carlos Echeverry, and set the stage for a cabinet shuffle aimed at shoring up his slumping approval ratings.
It was not immediately known when Cardenas, 50, who holds a doctorate in economics from the University of California at Berkeley, would take on his new role.
Santos, after naming Cardenas, said he was “designed to be finance minister.” He previously held ministerial posts in economic development and transport.
“Cardenas is an extremely well known and respected economist, with fiscally sound ideas, so from a market perspective this will be well received,” said Alberto Bernal, head of research for Bulltick Capital Markets in Miami.
“What’s more important now for the market is the political makeup for the entire Santos cabinet.”
Among other posts that may also be changed in the coming days are education, health, interior, agriculture and defense, according to government sources.
Cardenas, who helped preside over a boom in the mining and oil industries, will also represent the government on the central bank’s board and seek ways to bolster growth in an economy that is being hit by the international financial crisis.
Once an investment pariah as drug-trafficking insurgents kidnapped, killed and attacked rural areas with bombs, Colombia has seen a dramatic turnaround in the last decade, attracting record foreign investment.
The central bank meets Friday to vote on whether to cut the benchmark lending rate from 5 percent to boost a slowing economy. Echeverry is expected to attend that meeting.
The 61-year-old Santos has been under pressure from a constant stream of criticism from former President Alvaro Uribe and a growing number of attacks by leftist rebels, denting his once commanding popularity.
Santos did not say who would be the next minister of mines and energy.
Known for his lively language and joking with the media, Echeverry will be nominated for a top role in the International Monetary Fund, Santos said. He is credited with guiding a fiscal rule through Congress that aims to save money during boom times and balance the budget by 2014.
Whoever replaces Cardenas as energy minister will be the third person to hold the post in less than two years.
Cesar Diaz, head of the Colombian Mining Chamber, said he did not believe that would affect investor sentiment.
“Officials are important but more important than officials are the policies of the central government. In this case it won’t affect the sector,” Diaz said.
Others, however, said moving Cardenas to the finance ministry at a critical time for the mining sector when Colombia is trying to push through a raft of changes would be negative for industry.
Some analysts said Defense Minister Juan Carlos Pinzon could be among those leaving the cabinet after a rise in assaults by FARC rebels and the perception that security is getting worse.
Santos, credited with some of the biggest blows to the rebels, accuses foes of using attacks by rebels as a “political weapon” and dismisses claims by Uribe and his followers that he is failing on security.