Best Buy Co Inc (BBY.N), the largest U.S. consumer electronics chain, reported better-than-expected quarterly profit and sales, helped by strong demand for smartphones and large-screen TVs, sending its shares up over 8 percent.

Best Buy , whose profits have benefited from cost-cutting lately, will continue to focus on aggressively pursuing its cost cutting initiatives this year. In March, the company said it planned this year to start a cost-cutting effort to save $400 million over the next three years.

"These savings are not expected to begin until the back half of fiscal 2016," Chief Executive Hubert Joly said on an earnings conference call.

Since 2012, Best Buy has cut jobs, removed layers of management and closed stores.

Best Buy said its revenue growth in the United States was driven by sales of mobile phones bundled with billing plans by telecom carriers. Under these plans, telecom carriers allow customers to buy new phones for a low down payment and pay the remaining amount in installments along with monthly bills.

Revenue from the U.S. rose 1.4 percent to $7.9 billion in the first quarter. However, same-store sales fell 0.7 percent.

For the second quarter, the company said it expected "a flat to positive low-single digit revenue growth rate" in its U.S. business and "a flat to negative low-single digit revenue growth rate" in its overall business.

The total revenue growth forecast includes the impact of some store closures and consolidation of operations in Canada, the company's second largest market.

International revenue declined 22.1 percent to $668 million, due to an impact from foreign currency fluctuations and the loss of revenue from its Canadian operations.

The company's comparable online sales sharply decelerated and grew 5.3 percent this quarter from 29.2 percent in the same period last year due to pressure from rollout of initiatives like ship from store, softness in demand for large online categories like tablets and computers among others.

The net income attributable to Best Buy 's shareholders fell to $129 million, or 36 cents per share, in the first quarter ended May 2 from $461 million, or $1.31 per share, a year earlier.

Excluding items, the company earned 37 cents per share versus 35 cents in the same period a year ago.

Revenue fell 1 percent to $8.56 billion.

Analysts had expected a profit of 29 cents per share and revenue of $8.46 billion, according to Thomson Reuters I/B/E/S.

Best Buy 's shares were up 5.4 percent at $35.6 in mid-morning trade.