* Santos' approval increases in poll
* New minister to preside over oil, mining boom
By Helen Murphy
BOGOTA, Aug 30 (Reuters) - Colombian President Juan Manuel Santos named close ally Federico Renjifo as energy and mining minister on Thursday in part of a Cabinet shuffle as the leader begins pursuing a peace process with FARC rebels.
Renjifo replaces Mauricio Cardenas, who was appointed last week to head the Finance Ministry. Renjifo, an economist and lawyer, previously served as interior minister.
As Santos moves toward possible formal peace talks with the Revolutionary Armed Forces of Colombia, or FARC, Renjifo will likely become part of a discussion of how royalties from oil and mining companies are distributed throughout the nation.
Santos announced on Monday that exploratory conversations with the FARC were under way. The drug-funded group has complained that foreign companies benefit from the land at the expense of poor Colombians.
Renjifo will preside over an oil and mining boom that has helped bring in record foreign investment in the past few years as a U.S.-backed military offensive against insurgent groups improved security in key exploration areas.
"This is a ministry that's moving in the right direction, where there are some important decisions to be made and policies that need to be implemented," Santos said at the presidential palace after naming Renjifo, who also has served on the board of state oil company Ecopetrol.
"He is someone that has been involved in the energy sector for many years and he takes over at a very important time for this (economic) locomotive," Santos added.
The government has said the $330 billion economy could attract as much as $17 billion in foreign direct investment this year, up from $13.2 billion in 2011.
Colombia has become Latin America's fourth biggest oil producer over the past decade in great part because of a reduction in the numbers of FARC guerrillas able to launch attacks against key economic infrastructure.
The Marxist rebel group, which has fought successive governments for almost 50 years, remains a threat in some regions and has stepped up attacks this year on oil and mining installations in a bid to hobble the nation's major economic driver.
The attacks helped Santos' approval slide to 48 percent in June, according to a Gallup poll, but his numbers picked up again following his announcement last week that changes would be made to his Cabinet and speculation he would seek peace with the FARC.
In the latest Gallup poll published on Thursday, Santos' approval rose to 51 percent.
Colombia is hoping to lure more foreign partners to help develop the nation's potentially large copper deposits and create a world class gold mining business and meet its delayed target of 1 million barrels of oil a day.
Renjifo may confront a slowdown in demand for Colombia's commodities in coming years, with global markets rattled by signs of slowing growth in China, the world's second biggest economy, which could curb that country's enormous demand.