Complex sentence: From 1868 to 1871 he became Finance Minister under José Balta, signing with a French company the controversial contract "Hires Dreyfus," which granted the Dreyfus house of Paris the monopoly of the peruvian guano exportations.
Split into simpler sentences: From 1868 to 1871, he became Finance Minister under José Balta and was responsible for signing the so-called "Hires Dreyfus" treaty with a French. The treaty granted the Dreyfus house of Paris the monopoly of the Peruvian guano exportations.