The previous forecast put the growth rate at 7.6%.
"We have submitted to the Finance Ministry an adjusted forecast for 2008," Andrei Klepach said, without specifying the new figure.
The official said the adjusted forecast would be submitted to the government on August 7.
According to the economics ministry, Russia's GDP growth was 8% in the first half of this year, 8.4% in January-May and 8.5% in the first three months.
It was earlier reported that the ministry could raise its GDP growth forecast for 2008 from 7.6% to 7.8%. However, Deputy Prime Minister Alexander Zhukov told journalists on Wednesday that the indicator could reach 8% this year.
In 2007, GDP growth stood at 8.1%