* Reserves dip on valuation changes, firm dollar
* Data shows cbank did not build on reserves
JOHANNESBURG, Feb 5 (Reuters) - South Africa's net gold and foreign exchange reserves fell by 0.8 percent to $38.63 billion at the end of January, largely on changes in valuations led by the impact of a stronger dollar.
Reserve Bank data on its website on Friday showed net holdings fell from $38.96 billion while gross reserves were down slightly at $39.489 billion.
International Monetary Fund special drawing rights were little changed at $2.783 billion.
The data largely reflected valuation changes and analysts said it pointed to the central bank staying out of the market, despite recent warnings that the rand may be a bit strong.
"I am surprised that the Reserve Bank is not intervening in trying to build reserves (while the rand is strong)," Colen Garrow, economist at financial service group Brait, said.
Currency reserves were down by $124 million to $32.351 billion while gold reserves fell $83 million to $4.355 billion due to a firmer dollar and lower gold price.
"Due to the diversified nature of the foreign exchange reserves, the appreciation of the dollar against various other currencies impacted negatively on the foreign exchange reserves," the central bank said.
"The gold reserves also declined due to a lower gold price," it said, adding more foreign deposits from the government also dragged down net holdings.
While the dollar is the biggest foreign currency in South Africa's portfolio, it also has large holdings of euro and other currencies. The euro weakened to $1.3958 at the end of January from $1.4424 a month before.
The central bank has steadily lifted reserves over the past five years after it brought a long-standing negative position into balance in 2004.
In spite of government reservations about a relatively firm rand, its gross reserves still lag emerging market peers and foreign currency buying has been constrained by the cost of accumulating it, given a ballooning budget deficit and an already sharp increase in bond issuance.
A firm rand also helps in containing inflation which pushed back outside the top end of the bank's 3 to 6 percent target range in December. (Reporting by Gordon Bell; Editing by Kazunori Takada)