NECKARSULM, Germany (Reuters) - The contest for Nokia's (>> Nokia Oyj) maps business has become a three-way race between German carmakers, a consortium including Uber and Baidu, and a third group including China's Tencent and Navinfo, people familiar with the process said.

Finland's Nokia has started an auction of its maps business HERE while it completes its 15.6 billion euros ($17.2 billion) takeover of network equipment maker Alcatel Lucent (>> Alcatel Lucent).

German automakers Daimler (>> Daimler AG), BMW (>> Bayerische Motoren Werke AG) and Volkswagen's (>> Volkswagen AG) premium brand Audi have teamed up with private equity firm General Atlantic to form what is being described as the "Industry consortium", two sources familiar with the matter told Reuters on Thursday.

Nokia, Daimler, BMW and General Atlantic declined to comment.

The automakers have agreed to contribute potentially more than 700 million euros, but below 1 billion euros, said one auto industry source, who declined to be named. The consortium could be widened to include more carmakers, the source added.

Another group consists of Chinese media, mobile and Internet services firm Tencent Holdings (>> Tencent Holdings Ltd), Chinese map maker Navinfo Co. (>> NavInfo Co., Ltd.), and Swedish buyout firm EQT Partners AB, three sources who declined to be named said.

Navinfo and Tencent were not immediately available for comment. EQT declined to comment.

Private equity firm Apax has joined U.S.-based taxi service Uber and China's Baidu (>> Baidu Inc (ADR)) in a third consortium, a financial source who declined to be named said.

Apax and Uber declined to comment. Baidu was not immediately available for comment.

Analysts put the potential value of HERE at 2 billion euros to 4 billion euros.

Audi R&D boss Ulrich Hackenberg on Friday said he could imagine adding more partners to the consortium headed by luxury carmakers.

"There are many possibilities, it's still too early," Hackenberg said.

Nokia is in no hurry to sell HERE despite receiving high quality bids, the Finnish company's chief executive said in a trade magazine interview.

(Additional reporting by Gregory Roumeliotis, Irene Preisinger, Eric Auchard and Jussi Rosendahl; Writing by Edward Taylor; Editing by Mark Potter)

By Andreas Cremer and Arno Schuetze