UPDATE 2-T-Mobile says sets subscriber record in first quarter

(Adds quote by CEO, analyst, adds analyst estimates)

April 30 (Reuters) - T-Mobile US Inc said it added a record number of customers in the first quarter, blowing past its competitors as the company's aggressive discounts lured in subscribers

T-Mobile shares jumped 8.3 percent as the company that has billed itself as the "uncarrier" signed up 2.4 million subscribers in the first quarter, topping estimates of 932,000. That was more than its top three rivals combined, a first for the No. 4 mobile carrier in the United States.

"The 'uncarrier' strategy is working from a subscriber perspective and the market is responding to that," said Michael McCormack, an analyst at Jefferies.

Still, the mobile service provider lost $151 million, or 19 cents per share, in the quarter, compared with a profit of $107 million, or 20 cents per share, a year earlier.

Revenue rose 47 percent to $6.88 billion, compared with $4.68 billion in the year-ago quarter.

Analysts, on average, expected a loss of 19 cents per share on revenue of $6.92 billion, according to Thomson Reuters I/B/E/S.

It said earnings before interest, taxes, depreciation and amortization, or cash flow, fell 12.2 percent from the previous quarter to $1.1 billion due to additional costs from the sudden rise in subscribers.

T-Mobile, two-thirds owned by Deutsche Telekom AG , started to turn the corner last year after losing customers for four years, through aggressive marketing and heavy advertising for its wireless plans that have enabled it to grab market share.

The company launched a series of promotions this year, including eliminating contracts and introducing a billing plan for equipment that allows customers to pay for devices in installments. Analysts said the installment plans could pose a liability for the company if the economy turns sour as some customers may not be able to complete payments.

Yet T-Mobile Chief Executive Officer John Leger said the company's new subscribers have a better credit and revenue profile.

"There's no expectations on our part to sacrifice profitability for significant growth," said Leger.

"We are very pleased with economic systems we have going here with the 'uncarrier' move. These are high-quality customers so they have impact on lower churn," or customer defection rate, he said.

In the quarter T-Mobile added 1.3 million postpaid customers - those who pay monthly bills - and 465,000 prepaid customers, who pay for calls in advance.

Churn for postpaid service was 1.5 percent, down 20 basis points from the fourth quarter and off 40 basis points from a year ago.

T-Mobile stock rose $2.44 to $31.73.

(Additional reporting by Supantha Mukherjee and Soham Chatterjee; Editing by Joyjeet Das and Jeffrey Benkoe)