WASHINGTON, Feb 11 (Reuters) - The Federal Trade Commission has issued special orders to five big tech companies -- Alphabet's Google, Amazon.com, Apple , Facebook and Microsoft -- to provide information about mergers that were too small to report to antitrust agencies, the agency said on Tuesday.

The orders were issued as part of a study that the agency is doing into whether the companies buy up nascent or potential competitors, the agency said in a statement.

"This initiative will enable the commission to take a closer look at acquisitions in this important sector, and also to evaluate whether the federal agencies are getting adequate notice of transactions that might harm competition," FTC Chairman Joe Simons said in a statement. (Reporting by Diane Bartz, Editing by Franklin Paul)