UPDATE 1-Plantronics to buy video conferencing gear maker Polycom for $2 bln

(Adds details of the deal, background)

March 28 (Reuters) - Headsets maker Plantronics Inc said on Wednesday it would buy Polycom in a deal valued at $2 billion, two years after the video conferencing equipment maker was acquired by private equity firm Siris Capital.

The cash-and-stock deal comprises about $948 million in cash and Plantronics shares worth $358 million, as well as $690 million in debt.

Polycom shareholders will own about 16 percent of the combined company.

The transaction is expected to immediately add to Plantronics' adjusted earnings, and will save $75 million annually within one year of the deal's closing.

Plantronics said it intends to fund the cash portion of the offer with cash on hand and about $1.375 billion in debt financing.

Siris Capital Group had acquired Polycom for $1.7 billion in 2016, scuppering a three-month old deal with Canadas Mitel Networks Corp.

Wells Fargo Securities is the lead financial adviser to Plantronics and Foley & Lardner LLP is the legal adviser.

Moelis & Co LLC and Macquarie Capital are financial advisers to Polycom, while Sidley Austin LLP its legal adviser. (Reporting by Sonam Rai in Bengaluru Editing by Saumyadeb Chakrabarty)