June 5 (Reuters) - Lululemon Athletica beat Wall Street expectations for first-quarter revenue on Wednesday, as strong international business helped buffer a slowdown in consumer discretionary spending in its key North America market.

The company's shares, which have declined about 40% this year, rose more than 11% after the bell.

The company also approved a $1 billion increase to its stock repurchase program.

Despite slackening shopper appetite in the United States, strong China demand has helped sales for the brand, as customers look to refresh their wardrobes ahead of the summer season.

Comparable sales increased 6% for the company, with the Americas coming in flat compared to last year and a 25% jump in international business.

Lower discounts and strong full price selling has boosted its gross margin, which increased 20 basis points to 57.7%.

The athleisure apparel maker posts quarterly net revenue of $2.21 billion, above analysts' average estimate of $2.19 billion, according to LSEG data. (Reporting by Savyata Mishra in Bengaluru; Editing by Maju Samuel)