By Lars Mucklejohn British chipmaker Graphcore is reportedly exploring a sale to foreign buyers after struggling to reap the rewards of the boom in artificial intelligence. The Sunday Telegraph reported that the Bristol-based firm has been in talks over a possible deal with major tech companies to cover heavy losses, citing unnamed industry sources. Graphcore has failed to successfully cash in on the exploding market for AI chips despite large spending. The company has also grappled with the closure of its Chinese business over US chip controls. The firm, most recently valued at $2.8bn in late…