No-frill carrier IndiGo and Jet Airways have charged higher fares in several sectors than all other Indian carriers in July when the overall average airfares dropped due to lean passenger traffic, according to a DGCA data.

The data showed that IndiGo, Jet Airways and its no-frill arm JetKonnect charged an average of about 10-15% higher fares than other airlines.

The DGCA fare analysis for July showed that there was an overall dip in air fares in the lean travel month compared to those in June.

The fares dropped in 37 out of 48 sectors, mostly to non -metro Tier-II and Tier-III cities. The analysis, however, does not include major trunk routes on which the airlines have most flights and carry most of their passengers. While the highest fall in fares was recorded on Delhi- Gorakhpur route by Rs 6.3 a kilometre, the highest increase was averaged at Rs 2.1 per km on Mumbai-Nanded sector, the analysis showed.

On Delhi-Dibrugarh route, IndiGo charged Rs 9,425 as the average one-way fare compared with the industry average of Rs 8,361, while its average fare on Delhi-Dabolim (Goa) route was Rs 7,836 compared with the industry average of Rs 7,625.

Jet Airways charged Rs 12,001 and JetKonnect Rs 12,621 on Leh-Delhi sector, compared to the industry average of Rs 11,013. The Air India fare on this route was Rs 10,948.

Similarly, Jet's average fare on Port Blair-Delhi route was Rs 10,377, compared to Air India's Rs 8,027 and industry average of Rs 9,182.

The high airfares have been a major reason for domestic air travel, recording the steepest fall in seven years in July when 45.4 lakh people flew, 10% less than 50.4 lakh recorded in the same month last year.

While airline officials blame the high fares on rising fuel cost and hike in user development fees in Delhi and Mumbai, a financial think-tank cited the sharp rise in airfares as a reason to slash its forecast on air passenger traffic growth this year from 11 to 7%.

"We now expect air passenger traffic to grow by 7% in 2012-13 as against our earlier estimate of 11%," the Centre for Monitoring Indian Economy (CMIE) said in its latest report.