Altria is approaching an agreement to take a 35% stake in Juul

Altria Group Inc. is approaching an agreement to take a 35% stake in Juul Labs Inc. e-cigarette launch with a value of around 38 billion dollars, according to people familiar with the case, an investment that would make Juul one of most valuable private companies.

$ 12.8 billion cash injection could be announced as soon as this week, the people said. It would more than double what Juul was appreciated a few months ago, a sign of how fast the startup has grown and Altria's desire to find growth beyond its shrinking …