** Shares of British meal delivery company Deliveroo ROO.L rise as much as 17.7% to 173p

** Stock is top gainer on FTSE 250 index .FTMC, which is up 0.7%; on track for biggest one-day pct gain on record

** Co suspends 100 million pound ($133 million) buyback program days after it received a 2.7 billion pound takeover proposal from DoorDash DASH.O

** Deliveroo had said it would likely recommend the 180 pence-per-share offer to shareholders, subject to agreement on other terms

** ROO up about 4% so far this year

($1 = 0.7521 pounds)

(Reporting by Yamini Kalia in Bengaluru)

((Yamini.Kalia@thomsonreuters.com;))