CORRECTED - Vimpelcom cuts size of planned $1 bln loan-source

(Corrects new loan volume to euros in first paragraph)

MOSCOW, Sept 25 (Reuters) - Russian mobile operator Vimpelcom (VIP.N), which had planned to take a $1 billion loan, has opted for 500 million-600 million euros as credit conditions have tightened, a banking source said on Thursday.

The source said Vimpelcom had been planning to borrow at a rate of 180 basis points over LIBOR, but the rate would probably rise.

"They have to get credit approval all over again," the source said.

Vimpelcom borrowed $3.5 billion earlier this year to finance the acquisition of fixed line carrier Golden Telecom. (Reporting by Dmitry Sergeev)