Houston-based independent Lucas Energy Inc. has entered a joint venture with Marathon Oil (East Texas) LP, a unit of Marathon Oil Corp., to develop the Eagle Ford and Buda formations in Wilson County, TX. Marathon Oil has acquired 50% of the leasehold interest rights, representing about 1,000 net acres (below the base of the Austin Chalk formation) held by Lucas in a majority of Lucas' leases in Wilson County. Marathon Oil will be the operator, but Lucas will still own and operate rights above the Eagle Ford, primarily in the Austin Chalk, Lucas said. Lucas has a variety of working interests in Wilson County, which is south of San Antonio, ranging from 20% up to 100%. The Austin Chalk formation (and above), the current well bores and equipment, and the current production from the Austin Chalk and above are not included in the Marathon transaction. Financial details were not disclosed.