March 29 (Reuters) - Convenience store operator Arko Corp on Wednesday again urged TravelCenters of America Inc to consider its $1.4 billion buyout offer over BP's proposal.

TravelCenters recently rejected Arko's bid, saying the deal had a high level of execution risk due to the latter's inability to secure committed financing.

Arko said it had significant additional liquidity in the form of cash, cash equivalents and funds under its existing credit lines.

Oak Street, a division of asset management firm Blue Owl Capital, has also agreed to provide an additional $1.25 billion of capacity specifically to finance ARKO's acquisition of TravelCenters, the company said.

TravelCenters, which owns about 281 highway sites across 44 U.S. states, has accepted a $1.3 billion offer from BP, which is seeking to expand its retail network in a bet on biofuels and electric vehicle charging. (Reporting by Sourasis Bose in Bengaluru; Editing by Anil D'Silva)