Financial investors may buy Vattenfall grid-sources

*Vattenfall in exclusive talks to sell German grid- sources

*Selects group of financial investors for talks -sources

*Group has Goldman Sachs, Deutsche Bank, Allianz - sources

*Group bids at least 500 million euros - sources

By Peter Dinkloh and Philipp Halstrick

FRANKFURT, July 12 (Reuters) - A financial investor group has emerged as the final candidate to buy Vattenfall's German power grid in what would be one of the few European infrastructure deals this year, people familiar with the matter said.

A group consisting of the infrastructure funds of Goldman Sachs (GS.N), Deutsche Bank (DBKGn.DE) and Allianz (ALVG.DE) is in exclusive negotiations with the Swedish utility, three people familiar with the matter told Reuters.

The people asked not to be identified because the negotiations are confidential. Vattenfall declined to comment.