April 26 (Reuters) - Charter Communications posted larger-than-expected broadband subscriber losses and missed estimates for first-quarter profit on Friday, sending its shares down 3.4% before the bell.

The broadband market continues to see slowing growth at a time when Charter is also facing stiff competition from Comcast and AT&T.

Charter lost 72,000 internet customers in the first quarter, compared with estimates of losing 56,940 internet customers, according to Visible Alpha.

The company added 76,000 internet customers in the same period a year earlier.

Charter has previously benefited from the Affordable Connectivity Program (ACP), a government broadband internet subsidy program that is running out of money.

The coming quarters could be rocky for Charter with the end of ACP, brokerage Morningstar said last month.

The company's free cash flow in the first quarter was $358 million, compared with estimates of $519.3 million, hurt by higher spending related to its network expansion plans.

Charter posted a profit of $7.55 per share, missing estimates of $7.92, according to LSEG data.

The company reported revenue of $13.68 billion, in line with estimates.

Rival Comcast reported a loss of 65,000 broadband customers between January and March and said on Thursday that broadband losses would continue after it shed more customers than expected in the first quarter. (Reporting by Harshita Mary Varghese in Bengaluru; Editing by Shounak Dasgupta)