Pho, the Isis Equity Partners-backed Vietnamese fast-casual concept led by Stephen and Juliette Wall, is to strengthen its London estate after securing further sites in Balham and Covent Garden, M&C Report understands.

The 12-strong group will open in Bedford Hill, Balham next month and in Longacre, Covent Garden, early next year.

The company, which is coming off the back of its biggest London opening to date at One New Change, is thought to be progressing on a couple of other out of London opportunities.

Pho is believed to have enjoyed strong sales over the summer, experiencing double-digit growth across the majority of its estate in the three months to the end of September. The performance of its sites in Brighton and Islington were understood to have been particularly strong.

The group, which has also opened sites in Chiswick and Battersea Rise this year, already has an opening lined up in Birmingham Grand Central for next year and is believed to be close to agreeing on its first site in the north west.

The group, which is chaired by ex-Wagamama chief executive Steve Hill, is aiming grow its estate to up to 25 sites over the next two to three years.