Google+ attracts 25 mln visitors -comScore

* Google+ is fastest site to reach 25 mln visitors

* Facebook, Twitter took much longer to reach that size

* Fast growth early may not mean long-term success

By Alistair Barr

SAN FRANCISCO, Aug 2 (Reuters) - Google Inc's (GOOG.O) new social network has attracted 25 million users, making it the fastest website to reach that audience size, according to data released on Tuesday by comScore (SCOR.O).

Google+, launched in late June, had 25 million unique visitors as of July 24 and is growing at a rate of roughly one million visitors a day, comScore noted in a presentation.

In contrast, it took Facebook about three years to attract 25 million visitors, while Twitter took just over 30 months, according to comScore.

While the data show Google's latest attempt at breaking into social networking has started strongly, it may not mean the project is a long-term success. MySpace grew to 25 million unique visitors in less than two years -- faster than Facebook or Twitter. However, it's lost a lot of visitors in the past year, comScore data show.

Most Google+ visitors come from outside the United States. More than 3.6 million unique visitors have come from India, according to the data.

(Reporting by Alistair Barr; Editing by Phil Berlowitz)