Total SA is paying $2.5 billion for a share in India's Adani Green Energy Ltd. (AGEL) and its solar power assets, in what the French company said was its biggest investment yet in renewables.

As it furthers its strategic shift from fossil fuel, the deal will give Total a 20% stake in AGEL and a seat on its board, as well as a 50% share in the Indian firm's portfolio of solar power assets.

AGEL is controlled by Indian conglomerate Adani Group and has a market capitalization of about 1.483 trillion Indian rupees (US$20.25 billion).

Growing investor pressure has spurred Europe's top energy companies to outline plans to curb emissions and boost renewable energy output.

On Twitter, Total CEO Patrick Pouyanne said the deal with Adani "represents the biggest investment in renewables ever made by Total. It's a further demonstration of our transformation strategy. By 2020, Total will be in the top 5 for renewable energy."

Total's shares dipped 0.7% in early trading, as oil prices fell, but investment bank Barclays said Total was one of its top picks, with an "overweight" rating.

AGEL is targeting 25 gigawatts (GW) of renewable power generation by 2025, and Total said AGEL would make an important contribution to meeting Total's goal of 35 GW of gross production capacity from renewable sources by 2025 from around 9 GW now.

Last week, Total became the first major energy company to quit the main U.S. oil and gas lobby, the American Petroleum Institute, citing disagreements over the lobby's climate policies and support for easing drilling regulations.

(US$1 = 73.2320 Indian rupees)