Feb 18 (Reuters) - Macmahon Holdings Ltd MAH.AX :
* GBF GROUP RECEIVED CONDITIONAL LETTER OF INTENT FROM SILVER LAKE RESOURCES FOR FURTHER WORK AT MOUNT MONGER GOLD OPERATIONS
* GBF ESTIMATES VALUE OF NEW WORK WITH SILVER LAKE WILL ADD ABOUT $200 MILLION TO ITS ORDER BOOK
* SILVER LAKE & GBF WILL NEGOTIATE FORMAL MINING SERVICES AGREEMENT, WITH FINALISATION EXPECTED IN MARCH