Steep membership fees coupled with a calendar thin on world-class action so far could see the National Stadium lose several suite owners next year.

A raft of three-year executive suite memberships, which started when the stadium opened its doors in June 2014, are up for renewal, but The Sunday Times understands that several suite owners are unlikely to extend their contracts with the Singapore Sports Hub.

At least one suite owner is also believed to be locked in a legal dispute with the Sports Hub over alleged contractual breaches.

Speaking on condition of anonymity, a suite owner said: "The number of events is not commensurate with the membership fee. We totally overpaid.

"We were shown a calendar at first, admittedly one that was tentative. But the actual result fell far short of that."

A tentative event that was eye-catching to the suite owner was a plan to bring in top international cricket sides and Indian Premier League clubs but the idea was shelved over high costs.

Suite owners can attend all sporting events at the stadium. They also get tickets to two non-sporting events at the venue.

Another suite owner gave the event line-up a 5 out of 10 rating and said: "Only half the events were exciting and value for time and money. We are waiting for further indications on the line-up of events for (2017), which looks a little light at this stage."

The overriding sentiment is that the membership fee, which costs upwards of $70,000 a year depending on suite size, did not represent value for money, given the lack of world-class sporting events.

This year's sporting calendar makes for grim reading, with the highlights being a football friendly between Singapore and Malaysia in October and the HSBC World Rugby Singapore Sevens in April.

Non-sporting events included concerts by Madonna and Jay Chou, but there were complaints about the sound system.

In comparison, a five-seater suite at Manchester United's Old Trafford costs £22,743 (S$40,910) per season and includes all competitive fixtures the first team play at the stadium. The Red Devils played 29 games at home last season.

Suite owners are also less than enthralled by the National Stadium's 2017 calendar, with British rock band Coldplay's concert the only noteworthy act.

Other events being mooted include a U2 concert and a friendly match with Spanish football club Valencia. But, with three weeks left to next year, nothing else has been confirmed.

The 55,000-capacity National Stadium has 62 executive suites. Coupled with food and beverage expenses incurred by members, the suites generate more than $9 million annually for the Sports Hub.

Lacklustre event line-up aside, members are also disgruntled with the suites' restrictions. One owner said his guests were not allowed to join in the carnival atmosphere of April's HSBC World Rugby Singapore Sevens, which were staged on the lower levels.

Another lamented that tickets for full-day events cannot be used interchangeably should a guest decide to leave early.

The Sports Hub has held numerous meetings with suite owners to address these concerns. It is understood to have also offered members tickets to events held at the Kallang cluster, such as the Women's Tennis Association Finals at the Singapore Indoor Stadium, as a gesture of goodwill.

Mr Chin Sau Ho, the Sports Hub's senior director of corporate communications and stakeholder management, said: "We are aware that not all types of events may appeal to every suite owner. In this respect, we have also sought to expand the number of events offered in the National Stadium in the past few years."

Mr Chin said the new year will see "exciting and refreshing events" held at the stadium and that talks are ongoing with potential new suite owners.

He added: "We appreciate that the current economic environment is naturally of concern for many corporations and organisations seeking to optimise their budgets and spend for best returns.

"We therefore continue to build our calendar of activities and strive to attract a robust number and assortment of events so as to offer even more compelling content across the Sports Hub campus."

The National Stadium's high rental had reportedly put off many would-be event organisers previously, but it is believed to be adopting a more flexible approach now.

For instance, it is understood that organisers of the Singapore Rugby Sevens do not pay rent but instead share revenue with the Sports Hub.

But this change in approach might have come too late to allay the concerns of those whose memberships are expiring.

A suite owner said: "It's disappointing because the National Stadium is a great venue with a lot of potential. We understood it will take some time to secure good events but after more than two years, it still falls short of expectations."