MUMBAI, February 9 (Reuters) - Indian drugmaker Lupin Ltd reported a better-than-expected quarterly profit, helped by higher sales of its diabetes products in the United States, but cautioned growth in the next fiscal year would be muted due to rising competition. Lupin's generic versions of the diabetes drugs Fortamet and Glumetza have boosted its sales in its largest market in the past year, but rival generics are expected to hit sales in the coming months, Managing Director Nilesh Gupta told Reuters. To offset that, Lupin expects to launch about two dozen products in the fiscal year starting April 2017 in the United States, Gupta said on Thursday. The company launched four products in the United States over the three months ended December. Lupin's sales in North America, which accounts for almost half of its overall revenue, rose nearly 58 percent in the quarter. Like most of its peers, Lupin - the world's seventh-largest generic drugs maker - has been spending on building up its portfolio of niche products, such as respiratory devices, that are harder to make and therefore command higher prices and face limited competition. It is currently awaiting its first U.S. approval for a metered-dose inhaler to treat asthma. While rivals, including Cipla Ltd and Sun Pharmaceutical Industries Ltd, are also making inhalation devices, Gupta said he believed the market would remain lucrative in the long term. Earlier in the day, the Mumbai-based company reported a third-quarter net profit of 6.33 billion rupees ($94.44 million), up from 5.25 billion rupees a year ago. Analysts on average expected a profit of 6.29 billion rupees, according to Thomson Reuters I/B/E/S. The drugmaker's sales in India, its second-largest market, rose 12 percent from a year ago, but fell slightly versus the quarter ended September as distributors cut inventories after the government scrapped 500- and 1,000-rupee notes in November. Gupta said sales at home are expected to recover by the first quarter of the coming financial year, and would grow at 15 percent each year "for the foreseeable future".