Judgment :- 1. The defendant in O.S.No. 57 of 1978 is the appellant. In O. S. No. 2L of 1975 a decree had been passed against the present plaintiff as the surety and the present defendant as the principal debtor in respect of money due to the foreman of a chitty. They were held to be jointly and severally liable for the decree amount of Rs. 7,000/-. Since the defendant did not pay the amount, the plaintiff's property was proclaimed for sale and purchased by the decree holder at an auction on 3-2-1977 for a sum of Rs 7,000/-. On 18-4-1978, the auction purchaser re-sold the property for a sum of Rs. 10,000/-. 2. In the present suit, the plaintiff/ surety claims from the defendant a sum of Rs. 10,000/- said to be the loss suffered by him as a result of the sale of his property in execution of the decree in O. S. No. 21 of 1975. The court below passed a decree in favour of the plaintiff for the said sum of Rs. 10,000/-. 3. Shri. T. R. Raman Pillai appearing for the defendant/ appellant does not dispute that the defendant is liable to indemnify the surety in terms of S.145 of the Indian Contract Act, 1872. He, however, submits that the liability of the defendant is limited to Rs. 7,000/-. 4. S.128 of the Indian Contract Act provides: "128. The liability of the surety is co-extensive with that of the principal debtor unless it is otherwise provided by the contract." S.140 says: "140. Where a guaranteed debt has become due, or default of the principal debtor to perform a guaranteed duty has taken place, the surety, upon payment or performance of all that he is liable for, is invested of all the rights which the creditor had against the principal debtor." The liability of the surety is co-extensive with that of the principal debtor, and upon payment by the surety of the amount for which the principal debtor is liable, the surety is invested with all the rights which the creditor had against the principal debtor. 5. S.145 reads: "145. In every contract of guarantee there is an implied promise by the principal debtor to indemnify the surety; and the surety is entitled to recover from the principal debtor whatever sum he has rightfully paid under the guarantee, but no sums which he has paid wrongfully". 5. S.145 reads: "145. In every contract of guarantee there is an implied promise by the principal debtor to indemnify the surety; and the surety is entitled to recover from the principal debtor whatever sum he has rightfully paid under the guarantee, but no sums which he has paid wrongfully". The liability of the principal debtor to indemnify the surety is limited to the amount rightfully paid by the latter under the guarantee (see S.125 read with S.145). The surety was in the present case undoubtedly liable to pay the creditor the decree amount of Rs. 7,000/-. On his failure to pay that amount, his property was in execution proceedings sold for the like sum of Rs. 7,000/-. It is in respect of the loss thus sustained by the surety that be is entitled to be reimbursed by the principal debtor. The fact that the decree¬holder/auction-purchaser sold the property subsequently and obtained a profit on account of fluctuation in price is irrelevant to the question as to the liability of the defendant to indemnify the surety. 6. In the circumstances, we are of the view that the learned judge was in error in passing a decree in excess of Rs,7,000/-. The decree shall accordingly stand reduced to the said sum of Rs. 7,000/-. together with interest thereon at 6 per cent per annum and the proportionate cost. The appeal is allowed to this limited extent. Allowed.