* Shareholders to vote on 2013-15 board on April 9
* Diniz already chairman of Grupo Pao de Acucar
SAO PAULO Feb 21 (Reuters) - The Board of Directors of BRF Brasil Foods S.A., the world's largest poultry exporter, nominated Brazilian retail tycoon Abilio Diniz to be its new chairman, according to a securities filing on Thursday.
Shareholders will vote on the 2013-2015 board of BRF, as the company is known, on April 9.
Diniz, chairman of Grupo Pao de Acucar (GPA), will have to answer to widespread accusations that holding both positions is a conflict of interest.
BRF is a major supplier of GPA, according to Jean-Charles Naouri, the Chief Executive of French retailer Casino, which controls GPA, Brazil's top retailer.
While there is nothing in Diniz's shareholder pact with Casino preventing him from taking the reins of BRF, Naouri said on Thursday he hoped "ethical and governance principles would prevail".
Diniz has been buying shares of BRF over the past few weeks and as of Feb. 1 had amassed a 3.8 percent stake in the $19 billion company, according to newspaper Estado de Sao Paulo. (Reporting by Caroline Stauffer; editing by Andrew Hay)