Singapore Airlines (SIA) and payment network operator and global services company American Express have updated their co-branded credit cards.

In a joint statement, the firms said yesterday there will be new benefits such as exclusive SIA travel privileges with minimum spending - depending on the consumer's type of card - and faster ways to earn and redeem KrisFlyer rewards.

KrisFlyer is SIA's frequent flier programme, and the miles can be redeemed for travel on SIA and its units SilkAir, Scoot and Tigerair, among other partner airlines.

Ms Lee Wen Fen, SIA's senior vice-president of marketing planning, said the changes come as "part of our longstanding commitment to continually enhance the KrisFlyer programme".

Card members now earn up to 2.4 KrisFlyer miles per dollar spent, up from two miles per dollar spent previously, with no limit on miles awarded.

The firms added in a statement that they also offer customers "hassle-free automatic crediting of miles transfers to their KrisFlyer accounts with no conversion fees".

Depending on the card, consumers also get benefits such as complimentary upgrades from business class to Singapore Airlines Suites or first class, or 50 per cent savings on KrisFlyer miles redemption for award tickets.

Consumers can even save some money with a $150 cashback for bookings made on singaporeair. com, or get what is known as double KrisFlyer miles accrual vouchers. These vouchers can be used to earn twice the number of miles on selected flights.

Other perks unique to the co-branded cards include getting two KrisFlyer miles for every dollar spent on their sites such as singaporeair.com and silkair.com.

Mr Cheng Heng Chew, American Express' Singapore country manager, said over the last 15 years, the two firms have come up with four cards, and hope the changes bring a "more rewarding travel experience" for consumers.