Singapore public transportation operator SMRT Corp Ltd is considering an 800 million pound ($1.3 billion) takeover bid for unlisted British taxi company Addison Lee, Sky News said on Saturday.

Sky News, which did not cite a source, said SMRT is at the early stages of considering an offer.

SMRT, which operates Singapore subway lines and has bus and taxi services, did not confirm or deny the report.

"SMRT constantly looks out for investment opportunities that contribute to sustainable growth for our stakeholders," Benny Lim, its managing director for roads, said in an emailed response.

Private equity firm Carlyle Group, which bought a significant stake in Addison Lee last year, did not immediately respond to an email seeking comment.