(Adds estimate of deal value, history of deal talks, reasons for purchase, market conditions)
RIO DE JANEIRO, Nov 13 (Reuters) - BM&FBovespa SA , Latin America's largest exchange operator, said on Friday it made a non-binding offer for Cetip SA Mercados Organizados, valuing the Brazilian securities clearing house at about 10 billion reais ($2.6 billion).
The offer, part of a deal first announced earlier this month, values Cetip at 39 reais ($10.14) a share or 15.5 percent above its price on Oct. 30, the last day the shares traded before the planned purchase was announced, BM&FBovespa said in a statement.
BM&FBovespa SA and its rival Cetip have been discussing a merger to bolster their strength amid eroding confidence in Brazil's capital markets and a potential ratings downgrade of the country.
The announcement comes after years of speculation that BM&FBovespa could bid for Cetip in an effort to grow in registration and custody of fixed-income and credit-market instruments, segments in which BM&FBovespa has failed to gain market share.
Cetip is Latin America's largest securities clearinghouse.
A tie-up would make it harder for foreign rivals to expand in Brazil, the world's No. 2 emerging-market economy. The combined firm may also be able to cope better with deteriorating perceptions about market risks in Brazil. The country's economy, could shrink this year by the most in a quarter century.
In September, Standard & Poor's stripped Brazil of its investment-grade credit rating, increasing concern a second such move could soon follow as the country wrestles with a swelling budget gap and political turmoil. (Full Story)
A deal could seek to replicate recent industry tie-ups in which growing trading volumes helped boost the profitability and value of so-called market-structure firms, said Domingos Falavina, an analyst at JPMorgan Securities.
Rival exchanges usually combine operations to trim fixed costs. Revenue synergies can be harder to extract.
BM&FBovespa was created at the end of 2008 from the merger of commodities and futures exchange Bolsa de Mercadorias & Futuros SA and Bovespa Holding SA, which owns the São Paulo Stock Exchange.
Rivals CME Group Inc CME.O and Intercontinental Exchanges Inc ICE.N own stakes in both firms.
$1 = 3.8469 Brazilian reais Reporting by Jeb Blount; Additional reporting by Alberto Alerigi and Juliana Schincariol; Editing by Chris Reese and David Gregorio