CHICAGO, July 11 (Reuters) - Delta Air Lines ( DAL ) on

Thursday forecast lower profits in the current quarter than

analysts had expected, with the carrier citing discounting

pressure in the low end of the market.

The Atlanta-based carrier also reported a hit to

transatlantic bookings as travelers are avoiding Paris due to

the Olympic Games this summer.

Delta forecast an adjusted profit of $1.70-$2.00 per share

in the quarter through September compared with analysts

expectations of $2.05 per share, according to LSEG data.

Airlines are enjoying a summer travel boom, with more than 3

million people passing through U.S. airport security checkpoints

in a single day on July 7.

The boom has failed to lift earnings at most of the U.S.

carriers as excess industry capacity has undermined pricing

power. Major airlines have scheduled about 6% more seats in the

domestic market this month than a year ago, data from

consultancy Cirium shows.

It is having a dampening effect on airline fares. Average

round-trip ticket price for a U.S. domestic flight was $543 in

May, down 1% month-on-month and 3% lower from a year ago,

according to data from Airlines Reporting Corporation (ARC).

American and Southwest Airlines ( LUV ) have cut

their revenue forecast in the second quarter, citing discounting

pressure. In May, American's CEO Robert Isom said the domestic

supply and demand imbalance had led to more discounting activity

than a year ago.

While a shortage of planes due to production and engine

issues was expected to drive up airfares, industry officials and

analysts say a rush among airlines to capitalize on travel

demand has caused overcapacity. The impact is more telling on

ticket prices for main cabins.

Delta's revenue from main cabins, which generate about 49%

of its passenger revenue, was flat in the June quarter. In

contrast, revenue from premium cabins was up 10% year-on-year.

Many of the domestic carriers are now reworking their

networks and cutting capacity to protect their pricing power.

Delta expects its annual seat capacity growth to be 5%-6% in

the third quarter, compared with an 8% growth in the second

quarter. The moderation in capacity growth, however, is

estimated to drive up its non-fuel operating costs by 1%-2%

year-on-year.

The airline said its revenue suffered in the June quarter

due to the upcoming Olympic Games in Paris. Analysts and

industry officials expect the impact to persist in the current

quarter as high costs and safety worries are discouraging many

international travelers from visiting the French capital.

Last week, Air France-KLM warned of a 160 million

to 180 million euros ($173 million to $194.81 million) hit to

its unit revenues between June and August, saying international

markets were avoiding Paris.

Delta expects to post an operating margin of 11%-13% in the

third quarter, with a 2%-4% year-on-year increase in revenue.

Its reported an adjusted profit of $2.36 a share for the

second quarter, in line with LSEG's analysts expectations. The

company reaffirmed its forecast for a profit of $6 to $7 per

share in 2024 with a free cash flow of $3 billion-$4 billion.

($1 = 0.9240 euros)