UPDATE 1-PartyGaming says Q2 trading robust

* Q2 group revenue in line with Q1

* Q2 casino revenue up significantly

* Sees FY margins in line with 2008

LONDON, July 9 (Reuters) - British online gaming firm PartyGaming (PRTY.L) said on Wednesday trading in the second quarter had been robust with group revenue in line with that achieved in the first quarter.

The company said casino revenue had shown a significant increase from the first quarter despite a fall in the number of days players have been active due to seasonal factors.

It said the revenue growth had been driven by a substantial increase in the number of games offered by its main casino site, PartyCasino, which accounts for over 70 percent of its casino revenue.

PartyGaming said poker had also seen a marginal reduction in active player days due to seasonal factors as well as strong competition from United States-facing sites.

Sports betting revenue was down on the previous quarter reflecting a reduction in betting volume due to the end of the European football season, the company said.

PartyGaming said it has upped marketing spend in an effort to capitalise on the recent seizures of player funds from U.S.- facing sites by the Attorney's Office of the Southern District of New York.

The company said this has led to an increase in player numbers but also increased distribution costs.

Despite that, it said EBITDA margins for the full year are expect to be in line with 2008.

(Reporting by Matt Scuffham)