Sky News has learnt that KKR and Zenobe plan to announce this week that they have reached agreement on a deal valuing the business at about £800m.

The transaction will involve KKR buying a roughly-45% stake in Zenobe, positioning it alongside Infracapital as the joint largest shareholder.

In total, it involves a primary and secondary share sale worth approximately £500m, according to one investor.

Chaired by Steve Holliday, the former chief executive of National Grid, Zenobe describes itself as an international EV fleet and battery storage specialist.

It boasts a big share of the still-nascent UK electric bus sector, and counts National Express and Stagecoach, two of the country's biggest bus service operators, among its customers.

Zenobe repurposes electric vehicle batteries after their initial life, providing power solutions to industries such as film and events.

Founded in 2017, the company says it has raised about £925m in debt and equity funding to date.

Its smaller shareholders include the Japanese companies Tepco and Jera.

KKR declined to comment, while Zenobe could not be reached for comment.