* South Korea, Paraguay add gold to holdings.
Gold edged higher on Tuesday, defying a steady dollar, following data that showed central banks added to their bullion holdings in July and August, led by South Korea and Paraguay.
Spot gold rose 0.2 percent to $1,766.84 an ounce by 1200 GMT. The price has risen by 4.6 percent so far in September and is on course for a fourth consecutive monthly gain.
The rise has been sustained by anticipation that the U.S. Federal Reserve will keep credit flowing through the economy and interest rates low by buying government bonds.
"Ultimately, I think it's quite likely we will get above $1,800 before the year-end, so maybe a month of sideways trading possibly and then generally trending higher in the next six months to a year.
So far this year, central banks have added a net 262.1 tonnes to their reserves, compared with 203.39 tonnes in the first eight months of 2011.
Platinum edged up by 0.7 percent to $1,624.99 an ounce, while silver rose by nearly 1 percent to $34.24
