JOHANNESBURG (Reuters) - South Africa's biggest cement maker PPC said on Monday it expected its second half earnings to drop as much as 45 percent partly due to rising finance costs, sending its shares falling by more than 8 percent. PPC said earnings for the six months to end March 2015 would likely come in between 72 and 53 South African cents. Its shares initially lost 8.5 percent to a low of 21.66 rand but recovered to stand 3 percent lower at 1120 GMT. "Earnings per share for the first half of 2015 are anticipated to reflect a year-on-year decline mainly due to last year's once off tax credit combined with increased finance costs in this year," it said in a statement. PPC said earlier on Monday that sales volumes in the three months to the end of December had grown following its acquisition of a majority stake in Safika Cement in 2013.