BERLIN/FRANKFURT (Reuters) - German mechanical engineering group Voith [VOITH.UL] is selling its 25.1 percent stake in robotics maker Kuka to Chinese bidder Midea, paving the way for the merger to go through smoothly, people close to the deal said on Thursday.

A Voith spokesman said no decision has been taken on the sale of its Kuka stake and the company continued to consider all options. Midea and Kuka declined comment.

Midea has offered 4.5 billion euros ($5.1 billion) for Kuka, making it the biggest German industrial technology company to be targeted by a Chinese buyer in a wave of deals over recent months.

Voith, which took a stake in Kuka in late 2014, will be able to roughly double its investment by selling its stake to Midea.

In an initial response to Midea's buyout offer, the chief executive of Voith said last month that he viewed Kuka management's positive stance towards the Midea offer as premature.

But on June 10, Voith CEO Hubert Lienhard met Midea CEO Paul Fang in Hong Kong to discuss Midea's Kuka offer, the Voith spokesman said.

According to people familiar with that meeting, Fang replied to a question by Lienhard if Voith would be welcome to remain a 25 percent shareholder: "I cannot say you would."

Voith's owners resolved at a meeting on June 15 that it did not make strategic or financial sense for Voith to remain a minority shareholder alongside Midea, monthly Manager Magazin reported earlier.

News of Midea's bid for Kuka last month caused a furor among German politicians, though Midea has since said it would allow Kuka to operate independently and help it expand in China.

On a visit to Beijing this month, Chancellor Angela Merkel signaled that she would not try to prevent a takeover but also left the door open to German firms making a counter-offer.

However, no potential German or European rival bidder has emerged at this stage.

Another Kuka investor, Friedhelm Loh, had signaled in a newspaper interview that he may be willing to tender his shares.

While Loh has not said directly whether he planned to sell his 10 percent stake in Kuka to Midea, he added: "You have to ask yourself what an investment brings if you don't have a blocking minority at least."

(Reporting by Andreas Rinke and Alexander Hübner; Additional reporting by Denny Thomas, Arno Schuetze and Ilona Wissenbach; editing by Adrian Croft)