The Employees Provident Fund (EPF) has raised its stake in cement maker Lafarge Malayan Cement Bhd by buying an additional 1.74 mln shares between March 11 and 24 on the open market, the company said.  It said in a filing that EPF bought the shares in 4 tranches, increasing its holdings in the company to 278.79 mln shares.  No other details were given.