Oct 7 (Reuters) - Starry Inc said on Thursday it has agreed to go public through a merger with blank-check firm FirstMark Horizon Acquisition Corp (FMAC.N) in a deal that would value the broadband services provider at $1.66 billion. As part of the agreement, Starry will get $452 million in cash, including $130 million via private investment in public equity, and a concurrent equity financing round from investors such as Fidelity Management & Research Company, Tiger Global Management and affiliates of FirstMark Capital, among others. Funds from the transaction will be used to grow and deploy Starry"s services across the United States and to pay off existing debt, the company said. "We expect to launch in additional cities with this new capital that we"re raising," co-founder and Chief Executive Officer Chet Kanojia said. The deal comes at a time when special purpose acquisition company (SPAC) mergers in the U.S. capital market have seen a downturn in the recent months. Still, deal-making activity has set new records this year. Starry forecast annual revenues of over $1.1 billion in 2026. In 2020, the company"s top-line grew 187% to $13 million. The company expects to have over 25 million households under coverage by 2026, Kanojia said, up from 4.7 million households as of the second quarter of 2021. FirstMark, a SPAC backed by New York venture capital firm FirstMark Capital, raised $360 million through an upsized initial public offering in October last year. The combined firm will list on a national exchange under the symbol "STRY" after the merger, which is expected to close by the first quarter of next year. SPACs are shell companies with no business operations that are raised with the intent to merge with a private entity at a later date in an effort to take it public, bypassing a traditional IPO route. Reporting by Sohini Podder and Niket Nishant in Bengaluru; editing by Uttaresh.V and Diane Craft Our Standards: The Thomson Reuters Trust Principles.