CORRECTED - UPDATE 1-Telecinco says Euro 2008 ad boost disappointed

(Corrects 7th paragraph to say Telecinco's market share fell nine tenths of a percentage point, not nine points)

By Robert Hetz and Sarah Morris

MADRID, July 1 (Reuters) - Spain's victory in the Euro 2008 delivered record television viewing figures, but the soccer competition's contribution to Spanish advertising revenue disappointed, TV channel Telecinco (TL5.MC) said.

Spaniards watched a record amount of television in June as their team advanced towards the European title, an average of 226 minutes per person per day, according to data released on Tuesday by consultancy Barlovento.

However, the viewing boost was not enough to correct falling advertising revenues since May, Telecinco Chief Executive Giuseppe Tringali told a business forum in Madrid on Tuesday.

"In the (first) half, television (advertising) will have a negative trend," he said. "The Euro 2008 helped but not enough."

The outlook for the second half for advertising was also unclear, Tringali said. "Deals (with advertisers) are always being done later and visibility is becoming ever more difficult. Making a forecast about the end of the year is complicated."

However, Tringali said he was convinced Telecinco would continue to keep its position as the channel with the largest market share and would increase its share of a business which generates 3 billion euros ($4.73 billion) a year.

Telecinco, controlled by Italy's Mediaset (MS.MI), held on to its lead in June, according to the Barlovento data, but its share fell nine tenths of a percentage point to 18.7 percent, the channel's lowest ever.