Mendis, a former Sri Lanka captain, took over as interim coach in April after Dav Whatmore requested early leave from his contract, which expired at the end of May.
The BCCSL had hoped to find a permanent replacement for Whatmore in time for the West Indies tour, but all the frontline candidates were unavailable.
"Duleep (Mendis) will continue for the West Indies tour," said Anura Tennekoon, the BCCSL chief Executive.
The BCCSL has called off the search for a full-time coach until the cricket board elections on June 6.
"When
Englishman Bob Woolmer, New Zealander John Bracewell, Australian Steve Rixon and South Africa Graham Ford all made themselves unavailable after BCCSL approaches.
Most recently, Greg Chappell, the former Australian captain and coach of South Australia, halted negotiations because he could not commit to the post full time.
Sri Lanka play three one-day internationals and two Tests in the Caribbean, starting June 7.