BRUSSELS, March 21 (Reuters) - EU antitrust regulators will decide whether to clear Swedish security services group Securitas' $3.2 billion bid for Stanley Black & Decker's electronic security solutions business by April 27, a regulatory filing on Monday showed.

Securitas sought EU approval on March 18, the European Commission website showed.

In December, Securitas announced its bid to buy back the business unit it had sold to its U.S. rival in 2011. It hopes to close the deal in the first half of this year.

The EU competition agency can clear the deal with or without remedies or it can open a four-month long investigation if it has serious concerns after the end of the preliminary review. (Reporting by Foo Yun Chee; Editing by Alexander Smith and Mark Porter)