(Adds analyst's comment)
April 7 (Reuters) - Vocus Inc, a provider of cloud-based marketing and public relations software, said it would be bought by private equity firm GTCR Valor Merger Sub Inc for about $446.5 million.
GTCR will offer $18 per Vocus share, a premium of 48 percent to the stock's close on Friday.
Shares of Beltsville, Maryland-based Vocus rose 47 percent to $17.90 on the Nasdaq in early trading on Monday.
Vocus has recently shifted its focus to mid-sized companies from small businesses, but is finding it difficult to sell its software to its new target clients, who want more sophisticated products, Robert W. Baird & Co analyst Steve Ashley said.
"Vocus management evidently deemed it in the best interest of customers and employees to seek some outside expertise in completing the transition," he said in an email to Reuters.
Ashley said the valuation seemed fair and he did not expect other bidders for Vocus.
GTCR will also buy Vocus's Series A convertible preferred stock for $77.3 million.
Stifel was Vocus's financial adviser for the deal, which is expected to close in the second quarter of 2014. The deal includes a termination fee of $13 million.
(Editing by Don Sebastian and Kirti Pandey)