SOCCER officials breathed sighs of relief last night after the Urban Council agreed Mongkok Stadium will remain available for matches throughout the upcoming season. The Hong Kong Football Association had been concerned about Urban Council plans to close the stadium during the season in order to construct a roof over the main stand of the 8,500-seat venue. But now they've accepted a delay to the completion of the roof until the 1995 season in return for guaranteed use of the ground this term. If the worst comes to the worst the FA say they are prepared to do without the roof altogether in order to retain use of the stadium during the season. Last night's meeting of the HKFA management committee heard the news in a report from the FA's secretariat. Mongkok has been the main site for First Division matches since the Hong Kong Stadium closed for renovation early last year. The Urban Council, who own the stadium, had proposed shutting down the Mongkok arena between March and September to meet the FA's request for the erection of covers over the main stand, an action which would have thrown First Division fixtures into chaos. Such timing of the stadium closure would have left around 40 league matches outstanding. And with rental prices for the refurbished Hong Kong Stadium - due to open on March 11 - putting that beyond the FA's budget for all but the biggest matches, they would have been forced to hold games at the 2,100-seat Shamshuipo Sports Ground instead. Shamshuipo's reduced capacity would have meant serious loss of revenue to both the FA and the top clubs on the big crowd-pulling games. FA secretary Vincent Yuen Man-chuen met officials from the Urban Council and the Architectural Services Department on Tuesday to discuss the timing of construction work so that it would not affect the soccer fixtures. ''The ASD were adamant they needed six months to complete the project but we insisted on using the stadium until the end of May and they are now trying to work a way around it,'' FA assistant secretary Yung Hung-yau told the management committee yesterday. ''We suggested that perhaps they could split the project over two periods of three months instead, doing part of it during our off-season between June and September next year and completing it in the same period of 1995. ''The two Government departments have gone back to see if our proposal is viable and if not, we've proposed that the project should be scrapped altogether because we cannot do without the Mongkok Stadium.'' The First Division kicks off on September 19 with holders Eastern meeting arch-rivals South China at Mongkok. Newly-promoted clubs Rangers and Club meet in the second match with other first-round fixtures being Sing Tao against Instant-Dict, Kui Tan against Happy Valley and newcomers Voicelink taking on Kitchee. The bulk of First Division matches, even those between March and June, are scheduled to be held at Mongkok. But the FA has not yet arranged any matches for the Hong Kong Stadium, which will be able to hold 40,000 spectators when it is reopened. The Viceroy Cup semi-finals could be the first domestic soccer fixtures at the So Kon Po ground. At the moment the two matches are scheduled for March 24 and 26 but they will have to be brought forward if the Hong Kong Stadium is used because the international rugby sevens are on March 26 and 27. The FA management committee have decided to put the two semi-finals and all fixtures between March 13 and April 10 on hold, including the Viceroy Cup final which is tentatively scheduled for April 3. It was also decided that the regular admission charge be set at $40 but if both clubs agree they can apply to alter ticket prices with at least 10 days prior notice to the FA. Eastern and South China are the first to apply for a raise in ticket prices, pumping up the charge for their season opener to $70.