Specific financial details were not disclosed.
Under the agreement, LDK Solar will deliver 640 megawatts of multicrystalline solar wafers to Moser Baer over 10 years beginning in mid-2008 and running through 2017.
Moser Baer will make a "suitable advance payment" reflecting the contract value to LDK Solar, the company said.
LDK shares rose $1.47, or 4.9 percent, to $31.56 in aftermarket trading, after rising $2.59, or 9.4 percent, to $30.09 in the regular session.