* Agrees to buy further 29.6 pct of Serasa for $1.5 bln
* Deal takes total Serasa holding to 99.6 pct
* Shares up 3.5 percent, top FTSE riser
LONDON, Oct 23 (Reuters) - British credit information firm Experian has agreed to buy a further stake in its Brazilian affiliate Serasa from a group of banks for $1.5 billion in cash to take its holding to 99.6 percent, it said on Tuesday.
"We see significant potential for future growth in Brazil, and we are delighted to have the opportunity to further invest in this exciting region," Experian's chief executive Don Robert said in a statement.
Experian, best known for checking consumers' credit records on behalf of banks and retailers, is buying the 29.6 percent stake in Serasa from a group of four lenders - Itau Unibanco and Banco Bradesco Financiamentos of Brazil, Spain's Grupo Santander and Britain's HSBC .
The acquisition will be funded through Experian's existing bank loans, and comes five years after the credit checker first bought into Serasa.
Experian shares were up 3.5 percent at 1085 pence by 0825 GMT, making them the top riser in Britain's FTSE 100 share index . The stock has risen more than 20 percent since the start of the year, against a 5.5 percent rise for the index as a whole.
"We suspect investors may welcome the clarity that this announcement brings, given ongoing market speculation regarding a possible minority deal for several months," analysts at stockbroker Jefferies wrote in a note.
Experian has relied on strong growth in emerging market economies to help offset a downturn in bank lending in Europe and the United States since the onset of the 2008 crisis.
The Serasa takeover is expected to complete by the end of the year, Experian said.